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Prescaler? Suggestions anyone?
Hi all,
I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com |
Hi,
Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Cheers - Joe |
Hi,
Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Cheers - Joe |
In , "Harry \(SM0VPO\)"
wrote: Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com Man, if THIS ain't a trip -- a well-known, over-rated internet homebrew tech asking for help for a simple prescaler. Hey Harry, don't you know that the basic freshman-lab-grade Class B or C amplifier is nothing more than a divide-by-2 counter? If you have a bunch of 2N2222's, 2N2907's, or any transistor with an Ft above your high-freq limit, you have a divide-by-(n x 2) counter. Any advanced homebrewer should know that stuff cause it's basic theory. And for you to post such a question in alt.radio.pirate.... that's pretty pathetic, Harry. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , "Harry \(SM0VPO\)"
wrote: Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com Man, if THIS ain't a trip -- a well-known, over-rated internet homebrew tech asking for help for a simple prescaler. Hey Harry, don't you know that the basic freshman-lab-grade Class B or C amplifier is nothing more than a divide-by-2 counter? If you have a bunch of 2N2222's, 2N2907's, or any transistor with an Ft above your high-freq limit, you have a divide-by-(n x 2) counter. Any advanced homebrewer should know that stuff cause it's basic theory. And for you to post such a question in alt.radio.pirate.... that's pretty pathetic, Harry. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Harry \(SM0VPO\)" wrote in message . ..
Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com If you can live with a larger and binary division, there would be a prescaler that likely does work to that frequency limit in any digitally tuned FM broadcast radio. I have not looked up the upper frequency limit on these, but of course their needed range isn't much lower than your upper limit. I don't have a specific part number, I'm not even sure how much variety of ICs are used in these applications, but just about any scrap digitally tuned radio would offer up something. And if you need to find something commonly available but not rely on scrounging, then open one up and find the NTE replacement for the prescaler. Michael VE2BVW |
"Harry \(SM0VPO\)" wrote in message . ..
Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com If you can live with a larger and binary division, there would be a prescaler that likely does work to that frequency limit in any digitally tuned FM broadcast radio. I have not looked up the upper frequency limit on these, but of course their needed range isn't much lower than your upper limit. I don't have a specific part number, I'm not even sure how much variety of ICs are used in these applications, but just about any scrap digitally tuned radio would offer up something. And if you need to find something commonly available but not rely on scrounging, then open one up and find the NTE replacement for the prescaler. Michael VE2BVW |
"Harry (SM0VPO)" wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I'd be inclined to use a CPLD. The Xilinx XC9536 would be good to over 150 MHz and a suitable synchronous counter is quite trivial. 73, Leon -- Leon Heller, G1HSM http://www.geocities.com/leon_heller |
"Harry (SM0VPO)" wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I'd be inclined to use a CPLD. The Xilinx XC9536 would be good to over 150 MHz and a suitable synchronous counter is quite trivial. 73, Leon -- Leon Heller, G1HSM http://www.geocities.com/leon_heller |
"Joe McElvenney" wrote in message ... Hi, Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Any idea of the NEC part number ? Thanks |
"Joe McElvenney" wrote in message ... Hi, Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Any idea of the NEC part number ? Thanks |
Hi,
They are listed at - http://www.mouser.com/catalog/615/217.pdf and NEC have a data sheet on-line if you do a quick Google. I should point out that they are really only simple dividers with none of the front-end bits necessary to make a complete prescaler. I was thinking of using one with an old Racal 1991 VHF counter that has the built-in maths capability required to enable a non-decade pre-division. Cheers - Joe |
Hi,
They are listed at - http://www.mouser.com/catalog/615/217.pdf and NEC have a data sheet on-line if you do a quick Google. I should point out that they are really only simple dividers with none of the front-end bits necessary to make a complete prescaler. I was thinking of using one with an old Racal 1991 VHF counter that has the built-in maths capability required to enable a non-decade pre-division. Cheers - Joe |
I have thought about using one of the modern SM PLL chips such as the
National LMX2326 which can be progammed to give any division over a wide range (you do need a controller though to drive it) - you can access the main divider output directly and ignore the phase divider. These are widely available and pretty cheap. I would think you could do one one these "dead bug" with care, though they are SSOP. Of course if you are doing a PLL, why not use the whole chip? Richard Harry (SM0VPO) wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com |
I have thought about using one of the modern SM PLL chips such as the
National LMX2326 which can be progammed to give any division over a wide range (you do need a controller though to drive it) - you can access the main divider output directly and ignore the phase divider. These are widely available and pretty cheap. I would think you could do one one these "dead bug" with care, though they are SSOP. Of course if you are doing a PLL, why not use the whole chip? Richard Harry (SM0VPO) wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com |
Frank Gilliland wrote Man, if THIS ain't a trip -- a well-known, over-rated internet homebrew tech asking for help for a simple prescaler. And why not? I am the first to admit lack of experience any a field. You should not be afraid to ask, either. You learn a lot more than you do when you simply site there and ridicule people. ... over-rated ... ??? See what I mean ??? Superfluous words conveying no meaning, other than displaying emotions that one would hide in public to avoid embarrasment. Hey Harry, don't you know that the basic freshman-lab-grade Class B or C amplifier is nothing more than a divide-by-2 counter? If you have a bunch of 2N2222's, 2N2907's, or any transistor with an Ft above your high-freq limit, you have a divide-by-(n x 2) counter. Any advanced homebrewer should know that stuff cause it's basic theory. Not available in Sweden, just the usual 300MHz unity-gain (BC547, 557, etc), and the circuit stops operating at about 100MHz when the gain/pcb has become useless. I need RF transistors that are not available. ELFA only have no RF small signal devices. And for you to post such a question in alt.radio.pirate.... that's pretty pathetic, Harry. I was a pirate myself, LONG before I became an amateur. I have a lot of respect for the knowledge and experience of some of these so-called "pirates". I wonder how just many "pirates" you have spoken to on the HF bands? Certainly more than 0 and you were not even aware of it. Very best regards from Harry ( Writing from home this time ) harryvpo (at) hotmail (dot) com |
Frank Gilliland wrote Man, if THIS ain't a trip -- a well-known, over-rated internet homebrew tech asking for help for a simple prescaler. And why not? I am the first to admit lack of experience any a field. You should not be afraid to ask, either. You learn a lot more than you do when you simply site there and ridicule people. ... over-rated ... ??? See what I mean ??? Superfluous words conveying no meaning, other than displaying emotions that one would hide in public to avoid embarrasment. Hey Harry, don't you know that the basic freshman-lab-grade Class B or C amplifier is nothing more than a divide-by-2 counter? If you have a bunch of 2N2222's, 2N2907's, or any transistor with an Ft above your high-freq limit, you have a divide-by-(n x 2) counter. Any advanced homebrewer should know that stuff cause it's basic theory. Not available in Sweden, just the usual 300MHz unity-gain (BC547, 557, etc), and the circuit stops operating at about 100MHz when the gain/pcb has become useless. I need RF transistors that are not available. ELFA only have no RF small signal devices. And for you to post such a question in alt.radio.pirate.... that's pretty pathetic, Harry. I was a pirate myself, LONG before I became an amateur. I have a lot of respect for the knowledge and experience of some of these so-called "pirates". I wonder how just many "pirates" you have spoken to on the HF bands? Certainly more than 0 and you were not even aware of it. Very best regards from Harry ( Writing from home this time ) harryvpo (at) hotmail (dot) com |
what frequency steps are you looking for harry????
if its for the broadcast band then the philips range of tsa5511/12/14 are cheap and have upper operating range of 1300mhz, only trouble with them is 50khz steps..pic codes available on the net...otherwise the mc 145170 is a good choice, operates up to 170mhz..but is serial controlled as well.... g0zen simon "Richard Hosking" wrote in message . au... I have thought about using one of the modern SM PLL chips such as the National LMX2326 which can be progammed to give any division over a wide range (you do need a controller though to drive it) - you can access the main divider output directly and ignore the phase divider. These are widely available and pretty cheap. I would think you could do one one these "dead bug" with care, though they are SSOP. Of course if you are doing a PLL, why not use the whole chip? Richard Harry (SM0VPO) wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com |
what frequency steps are you looking for harry????
if its for the broadcast band then the philips range of tsa5511/12/14 are cheap and have upper operating range of 1300mhz, only trouble with them is 50khz steps..pic codes available on the net...otherwise the mc 145170 is a good choice, operates up to 170mhz..but is serial controlled as well.... g0zen simon "Richard Hosking" wrote in message . au... I have thought about using one of the modern SM PLL chips such as the National LMX2326 which can be progammed to give any division over a wide range (you do need a controller though to drive it) - you can access the main divider output directly and ignore the phase divider. These are widely available and pretty cheap. I would think you could do one one these "dead bug" with care, though they are SSOP. Of course if you are doing a PLL, why not use the whole chip? Richard Harry (SM0VPO) wrote in message ... Hi all, I am having a spot of bother with prescaler chips. Basically I need to find one at the right price and availability. US$5 each is reasonable, but where from? Is there one available that is not obsolete? I live in Sweden and my local component shop is ELFA (Swedens answer to RS). They don't sell ANY digital divider that operates above 50MHz, except for the 74F163 and I cannot come up with a reliable interface circuit to couple an oscillator into it at over 100MHz. I found the MB501 (MC12022, SP8704) but it is obsolete and cannot find a reliable source. I bought a couple, but that source dried up. All I need is a divider chip that will accept a small signal up to 150MHz, is available, cheap(ish) and will divide down to under 10MHz so that I can use CMOS to process a synthesiser. A parallel-load synthesiser chip with in-built 150MHz prescaler would do. I have used "Teleport" to download over 50,000 pdf datasheets without any luck. I have gone through most of them, but it takes a fair bit of time. If anyone has a helpful suggestion I would appreciate it. BR from Harry - SM0VPO http://w1.859.telia.com/~u85920178/ harryvpo (at) hotmail (dot) com |
"Joe McElvenney" wrote in message ... Hi, Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Cheers - Joe Hi Joe, Many thanks for the information. You have been a great help; exactly what I was alooking for. I keep having trouble buying this sort of specialised RF component. Mant thanks again for your help. BR Harry |
"Joe McElvenney" wrote in message ... Hi, Mouser have some NEC pre-scalers (3GHz max) for $2.92 a throw. Cheers - Joe Hi Joe, Many thanks for the information. You have been a great help; exactly what I was alooking for. I keep having trouble buying this sort of specialised RF component. Mant thanks again for your help. BR Harry |
My point was that the art of homebrewing loses something when it's reduced
to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. I can agree with you, but only up to a point, but do you never think that "them there chips" can possibly be used as a tool? A component? A lot depends upon where you draw that line between what you call homebrew and black-box. Do you not think that an Operational Amplifier, like the UA741, is a component? or would you rather use a slack-handfull of transistors every time you need an Operational amplifier. I personally put the prescaler chip in the same category as the OpAmp. ... where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. I get a great kick out of using CMOS and TTL chips. For example, one CD4007 can be used to build a complete superhet receiver. If I want a VHF synthesiser then I have absolutely no hesitation to using a couple of CD4000 chips and a prescaler. Logic, to me, is also homebrew. As I said before, it all depends upon where you draw the line. Try a simple flip-flop. Two transistors, that's all. There are probably a few dozen schematics on the net and dozens more at the public library (you do have public libraries in Sweden, don't you?). I didn't have to search for a circuit, but using simple transistors I have a circuit that is stable, but only up to about 95MHz. Here in Sweden, the ONLY non-power RF transistor I can find in Sweden is the 2N2369 (NPN) and it is that transistor that has increased the operating freq. of my stage to 96MHz. I have also tried just a simple schmitt trigger circuit and again, about 100MHz is the top limit for conventional transistors. Anyway, I am still having fun on the workbench and I will continue to do so. When I don't I will probably join all the others who are sick of radio and homebrew and get on the Internet. Prabably even subscribe to a hamradio newsgroup, such as "rec.radio.amateur.homebrew" and maybe even communicate with othere without the QRM. Best regards - Harry (SM0VPO) (If it feels good - do it!) |
My point was that the art of homebrewing loses something when it's reduced
to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. I can agree with you, but only up to a point, but do you never think that "them there chips" can possibly be used as a tool? A component? A lot depends upon where you draw that line between what you call homebrew and black-box. Do you not think that an Operational Amplifier, like the UA741, is a component? or would you rather use a slack-handfull of transistors every time you need an Operational amplifier. I personally put the prescaler chip in the same category as the OpAmp. ... where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. I get a great kick out of using CMOS and TTL chips. For example, one CD4007 can be used to build a complete superhet receiver. If I want a VHF synthesiser then I have absolutely no hesitation to using a couple of CD4000 chips and a prescaler. Logic, to me, is also homebrew. As I said before, it all depends upon where you draw the line. Try a simple flip-flop. Two transistors, that's all. There are probably a few dozen schematics on the net and dozens more at the public library (you do have public libraries in Sweden, don't you?). I didn't have to search for a circuit, but using simple transistors I have a circuit that is stable, but only up to about 95MHz. Here in Sweden, the ONLY non-power RF transistor I can find in Sweden is the 2N2369 (NPN) and it is that transistor that has increased the operating freq. of my stage to 96MHz. I have also tried just a simple schmitt trigger circuit and again, about 100MHz is the top limit for conventional transistors. Anyway, I am still having fun on the workbench and I will continue to do so. When I don't I will probably join all the others who are sick of radio and homebrew and get on the Internet. Prabably even subscribe to a hamradio newsgroup, such as "rec.radio.amateur.homebrew" and maybe even communicate with othere without the QRM. Best regards - Harry (SM0VPO) (If it feels good - do it!) |
Frank Gilliland wrote:
My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. [...] where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. Fair enough - only you can decide what you enjoy. When you post to the group, we know where you're coming from, so we can interpret accordingly. But only I can decide what I enjoy, only Harry what he enjoys, and so on for every individual. Amateur radio and electronics is about doing what each of us personally likes, not what we "should" or "must". You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
Frank Gilliland wrote:
My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. [...] where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. Fair enough - only you can decide what you enjoy. When you post to the group, we know where you're coming from, so we can interpret accordingly. But only I can decide what I enjoy, only Harry what he enjoys, and so on for every individual. Amateur radio and electronics is about doing what each of us personally likes, not what we "should" or "must". You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
In , "Ian White, G3SEK"
wrote: Frank Gilliland wrote: My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. [...] where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. Fair enough - only you can decide what you enjoy. When you post to the group, we know where you're coming from, so we can interpret accordingly. But only I can decide what I enjoy, only Harry what he enjoys, and so on for every individual. Amateur radio and electronics is about doing what each of us personally likes, not what we "should" or "must". You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , "Ian White, G3SEK"
wrote: Frank Gilliland wrote: My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. [...] where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. Fair enough - only you can decide what you enjoy. When you post to the group, we know where you're coming from, so we can interpret accordingly. But only I can decide what I enjoy, only Harry what he enjoys, and so on for every individual. Amateur radio and electronics is about doing what each of us personally likes, not what we "should" or "must". You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Frank Gilliland wrote:
You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? I honestly don't share that compulsion to classify other people's projects as either "homebrew" or not. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
Frank Gilliland wrote:
You are entitled to your own opinions about other people's preferences, Frank, but it's disrespectful to post them here as personal criticisms (and it doesn't encourage the rest of us to respect you). Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? I honestly don't share that compulsion to classify other people's projects as either "homebrew" or not. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
Frank Gilliland wrote:
My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. For example, the MAX038 is a chip that is a ready-made 0-20 MHz function generator with sweep, variable duty cycle, frequency modulation, and a phase discriminator. I'm sure that sounds cool to some, but if all you need is a 100 kHz square wave, why not learn how to build a square-wave oscillator with one or two transistors? And if you want a function generator, where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. I guess you wind your own capacitors, and collect lamp black to make your own resistors? there are tradeoffs in any project. Sure you could build a 50 pound toy that uses 200 watts to do a simple project, or do the same job in a handheld device that runs for weeks off a couple AA cells. Homebrewing is using what you can get to build what you want, as well as to meet the desired specifications. I started working with used parts in the '60s, but over the years I have moved on to more advanced projects. My biggest project to date, was building CH 58 TV in Destin, Florida with mostly defective and damaged 30 to forty year old broadcast equipment. It was a real challenge finding, or making replacement parts fore the RCA TTU-25B transmitter, and other old equipment. it was more of a restoration and homebrew project than it was meeting the deadline on the FCC construction permit. I ended up working as an engineering tech at L-3Com/Microdyne working on $80,000 telemetry receivers, and still design projects at home. I am working on some kits to allow people to build some test equipment they can't afford new, and don't need the performance of brand new Agilent or Tektronix equipment. It is cheaper to use "Chips", rather than discrete parts in a lot of circuits, and they design works better, too. Homebrewing should be used to learn something, and if you want to remain at the lowest level, enjoy yourself, but don't ridicule others who want to learn newer methods. -- Michael A. Terrell Central Florida |
Frank Gilliland wrote:
My point was that the art of homebrewing loses something when it's reduced to just plugging in a chip. Seems like everyone is ignoring how the circuits work and taking the 'black-box' approach instead. For example, the MAX038 is a chip that is a ready-made 0-20 MHz function generator with sweep, variable duty cycle, frequency modulation, and a phase discriminator. I'm sure that sounds cool to some, but if all you need is a 100 kHz square wave, why not learn how to build a square-wave oscillator with one or two transistors? And if you want a function generator, where's the fun in just hooking up power to a chip? That's not homebrewing, at least not in my book. I guess you wind your own capacitors, and collect lamp black to make your own resistors? there are tradeoffs in any project. Sure you could build a 50 pound toy that uses 200 watts to do a simple project, or do the same job in a handheld device that runs for weeks off a couple AA cells. Homebrewing is using what you can get to build what you want, as well as to meet the desired specifications. I started working with used parts in the '60s, but over the years I have moved on to more advanced projects. My biggest project to date, was building CH 58 TV in Destin, Florida with mostly defective and damaged 30 to forty year old broadcast equipment. It was a real challenge finding, or making replacement parts fore the RCA TTU-25B transmitter, and other old equipment. it was more of a restoration and homebrew project than it was meeting the deadline on the FCC construction permit. I ended up working as an engineering tech at L-3Com/Microdyne working on $80,000 telemetry receivers, and still design projects at home. I am working on some kits to allow people to build some test equipment they can't afford new, and don't need the performance of brand new Agilent or Tektronix equipment. It is cheaper to use "Chips", rather than discrete parts in a lot of circuits, and they design works better, too. Homebrewing should be used to learn something, and if you want to remain at the lowest level, enjoy yourself, but don't ridicule others who want to learn newer methods. -- Michael A. Terrell Central Florida |
Harry,
have a look at the following page: http://www.xs4all.nl/~barendh/Indexeng.htm He seem to stock several old Plessey prescalers, and it should keep you going for a while. I guess eventually these chips WILL be nowhere to be found within a few years time but that is evolution.... One non-obsolete chip-source would be Peregrine, http://www.peregrine-semi.com/prd_pll.html they have some neat parallell programmed IC's that runs to over 3 GHz. They are an improved Qualcomm Q3036 which can be found as surplus And there is several more interesting IC, not only PLL and prescalers but complete PLL with internal EPROM which keeps the serial programmed data even if one shut off the power. Great for that miniaturized project!! GL -Lasse SM5GLC On Fri, 15 Aug 2003 08:26:47 +0200, "Harry \(SM0VPO\)" wrote: |
Harry,
have a look at the following page: http://www.xs4all.nl/~barendh/Indexeng.htm He seem to stock several old Plessey prescalers, and it should keep you going for a while. I guess eventually these chips WILL be nowhere to be found within a few years time but that is evolution.... One non-obsolete chip-source would be Peregrine, http://www.peregrine-semi.com/prd_pll.html they have some neat parallell programmed IC's that runs to over 3 GHz. They are an improved Qualcomm Q3036 which can be found as surplus And there is several more interesting IC, not only PLL and prescalers but complete PLL with internal EPROM which keeps the serial programmed data even if one shut off the power. Great for that miniaturized project!! GL -Lasse SM5GLC On Fri, 15 Aug 2003 08:26:47 +0200, "Harry \(SM0VPO\)" wrote: |
http://www.peregrine-semi.com/prd_prescaler.html
:2 , :4 or :8 DC to 1GHz Buy online, price seems to be less than $3 -Lasse SM5GLC |
http://www.peregrine-semi.com/prd_prescaler.html
:2 , :4 or :8 DC to 1GHz Buy online, price seems to be less than $3 -Lasse SM5GLC |
"Harry - SM0VPO" ) writes:
As stated, the basic problem is getting a chip that is available, cheap and is likely to be available next year. The MB501 (SA701, MC12022, SP8704) is now classed as "obsolete" and one of my sources has also dried up. By the way, the TDA7000 is also obsolete and is soon to be joining the ZN414/5/6 and TCM3105 chips in the depths of obscurity. BR Harry - SM0VPO Do they have really cheap FM broadcast band only pocket radios over there, that tune with one button (and have a second button to reset to the bottom of the band)? They're everywhere here, and I've seen them for as low as $1.99 Canadian. Curious, I bought one at that price. No cermic filter, so it's using an oddball scheme. My first thought was that it was a TDA7000; as I mentioned a couple of weeks ago, the number on the IC was barely visible. So I looked up the TDA7000 on the web (it was easier than digging out the paper datasheet), and clearly it was not a match. But Signetics had pointers to a couple of other similar ICs, ie converting down to 70KHz where active filters can be used, and that frequency locked loop scheme. One of them was a match, if I'm remembering a 7088. I don't know how the specs generally compare with the TDA7000, but this IC has the logic in place for the two button tuning scheme. Obviously these are being put into products (I always wondered if the TDA7000 actually was put into commercial products), and hence there is an available source. Maybe not as IC, but the cheap radio is there. The IC is surface mount, but it's already soldered to a circuit board. Change the required parts, and you've got the radio or IF strip. Michael VE2BVW |
"Harry - SM0VPO" ) writes:
As stated, the basic problem is getting a chip that is available, cheap and is likely to be available next year. The MB501 (SA701, MC12022, SP8704) is now classed as "obsolete" and one of my sources has also dried up. By the way, the TDA7000 is also obsolete and is soon to be joining the ZN414/5/6 and TCM3105 chips in the depths of obscurity. BR Harry - SM0VPO Do they have really cheap FM broadcast band only pocket radios over there, that tune with one button (and have a second button to reset to the bottom of the band)? They're everywhere here, and I've seen them for as low as $1.99 Canadian. Curious, I bought one at that price. No cermic filter, so it's using an oddball scheme. My first thought was that it was a TDA7000; as I mentioned a couple of weeks ago, the number on the IC was barely visible. So I looked up the TDA7000 on the web (it was easier than digging out the paper datasheet), and clearly it was not a match. But Signetics had pointers to a couple of other similar ICs, ie converting down to 70KHz where active filters can be used, and that frequency locked loop scheme. One of them was a match, if I'm remembering a 7088. I don't know how the specs generally compare with the TDA7000, but this IC has the logic in place for the two button tuning scheme. Obviously these are being put into products (I always wondered if the TDA7000 actually was put into commercial products), and hence there is an available source. Maybe not as IC, but the cheap radio is there. The IC is surface mount, but it's already soldered to a circuit board. Change the required parts, and you've got the radio or IF strip. Michael VE2BVW |
Frank Gilliland ) writes:
Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? I think there's a vast difference between that scenario, and building with ICs. In your example, they are mere cosmetic work. But when building with an IC, you will have to actually build something around it in order to get something useful. I am a bit surprised that you hold this opinion this late in the game. Clearly, it was not an uncommon opinon thirty or so years ago, when people would write to the magazines and complain about so many ICs being used, and about how the internal diagram of the IC was not shown. A lot of that could be discounted as a transitional reaction, that since ICs were new people were reacting to the newness rather than an absolute reaction to ICs being "cheating". At least thirty years on, it's hard to imagine that there are people who haven't adapted. As others have pointed out, one can go down through a spiral to an absolute level of "homebrew", but everything would be pretty bulky then. Of course, early hams built their capacitors and all that, but it was more necessity than some hard core belief. Once you could get commercially available components, then they were used unless a) someone was curious about making a capacitor or b) what was exactly needed wasn't available. There are some borderline parts. It hardly makes sense to buy a commercially made coil if you can wind one yourself, but that's not because everyone should be making everything, but because if someone isn't winding, they may not realize it is a simple thing, and winding will save money. What ICs have done is allow for a level of complexity that wasn't available before them. Sure, there were PLLs described in the ham magazines using tubes, but they were as complicated as a simple superhet receiver. I can remember seeing tube based synthesizers, using multiple crystals mixed together, and they were more complicated than a full blown transmitter. If you want to build up a whole synthesizer from transistors, it's going to be terribly bulky. I suspect few will go to that trouble, and instead making something simple but which won't give the performance of a synthesizer. There is so much that can be built nowadays that virtually nobody would consider building in the tube era. So I dismiss your hardcore view on this. On the other hand, there is validty in constantly thinking through whether something should be done with transistors or ICs. One shouldn't build with ICs for the sake of building with them; if two transistors out of a scrap VCR and some other components from it flash an LED perfectly well, then what's the point of using an expensive and hard to get IC that exists only to flash LEDs? If you don't lose anything in performance, and only a little space, then you might as well use readily available scrap transistors to build an IF strip, than spend money and time buying an IC via mail order. If two transistors will supply a suitable prescaler for Harry's project, then it likely is a good choice, because it's easier to find transistors than prescaler ICs. But these are design decisions, not some rhetoric about how everything must be made from scratch. Any time something is designed, it's important not just to look at the way to do it, but at other alternatives, because people often do get blocked by looking down only one path. For instance, as I write this it occured to me that it might be easier for Harry to mix the VCO signal down to a frequency where the average logic IC can work. You don't have to find a prescaler, and the design's frequency steps won't be limited by the division of that prescaler. There are various mixer schemes that will result in the needed frequency. There may be reasons for not doing it this way, but it may not even be explored because Harry hasn't given this alternative any thought. Michael VE2BVW |
Frank Gilliland ) writes:
Let me ask you a simple question: Suppose someone buys an SP-600, mounts some chrome knobs, spray-paints his name on the front panel, then posts on the newsgroup saying, "Hey, look what I built!" Would you call that "homebrew"? I think there's a vast difference between that scenario, and building with ICs. In your example, they are mere cosmetic work. But when building with an IC, you will have to actually build something around it in order to get something useful. I am a bit surprised that you hold this opinion this late in the game. Clearly, it was not an uncommon opinon thirty or so years ago, when people would write to the magazines and complain about so many ICs being used, and about how the internal diagram of the IC was not shown. A lot of that could be discounted as a transitional reaction, that since ICs were new people were reacting to the newness rather than an absolute reaction to ICs being "cheating". At least thirty years on, it's hard to imagine that there are people who haven't adapted. As others have pointed out, one can go down through a spiral to an absolute level of "homebrew", but everything would be pretty bulky then. Of course, early hams built their capacitors and all that, but it was more necessity than some hard core belief. Once you could get commercially available components, then they were used unless a) someone was curious about making a capacitor or b) what was exactly needed wasn't available. There are some borderline parts. It hardly makes sense to buy a commercially made coil if you can wind one yourself, but that's not because everyone should be making everything, but because if someone isn't winding, they may not realize it is a simple thing, and winding will save money. What ICs have done is allow for a level of complexity that wasn't available before them. Sure, there were PLLs described in the ham magazines using tubes, but they were as complicated as a simple superhet receiver. I can remember seeing tube based synthesizers, using multiple crystals mixed together, and they were more complicated than a full blown transmitter. If you want to build up a whole synthesizer from transistors, it's going to be terribly bulky. I suspect few will go to that trouble, and instead making something simple but which won't give the performance of a synthesizer. There is so much that can be built nowadays that virtually nobody would consider building in the tube era. So I dismiss your hardcore view on this. On the other hand, there is validty in constantly thinking through whether something should be done with transistors or ICs. One shouldn't build with ICs for the sake of building with them; if two transistors out of a scrap VCR and some other components from it flash an LED perfectly well, then what's the point of using an expensive and hard to get IC that exists only to flash LEDs? If you don't lose anything in performance, and only a little space, then you might as well use readily available scrap transistors to build an IF strip, than spend money and time buying an IC via mail order. If two transistors will supply a suitable prescaler for Harry's project, then it likely is a good choice, because it's easier to find transistors than prescaler ICs. But these are design decisions, not some rhetoric about how everything must be made from scratch. Any time something is designed, it's important not just to look at the way to do it, but at other alternatives, because people often do get blocked by looking down only one path. For instance, as I write this it occured to me that it might be easier for Harry to mix the VCO signal down to a frequency where the average logic IC can work. You don't have to find a prescaler, and the design's frequency steps won't be limited by the division of that prescaler. There are various mixer schemes that will result in the needed frequency. There may be reasons for not doing it this way, but it may not even be explored because Harry hasn't given this alternative any thought. Michael VE2BVW |
"Michael Black" wrote in message ... But when building with an IC, you will have to actually build something around it in order to get something useful. SNIP thirty or so years ago, when people would write to the magazines and complain about so many ICs being used, and about how the internal diagram of the IC was not shown. A lot of that could be discounted as a transitional reaction, that since ICs were new people were reacting to the newness rather than an absolute reaction to ICs being "cheating". Over 30 years ago I homebrewed a PDP-8 work-alike computer. It was based on the PDP-8 instruction set. I've never seen PDP-8 electrical or detailed logic diagrams. I used ICs, but none more complex than a 4-bit adder. The 7400-series was then too expensive for me, so I used a cheaper compatible Signetic series in most cases. My choice to use ICs was based on a desire to finish the project within a reasonable time - which I did. There would have been too many parts going all-discrete. Of course discrete transistors were used as lamp drivers, to drive the core memory select lines, and in the voltage regulators. At least thirty years on, it's hard to imagine that there are people who haven't adapted. Even using simple digital ICs, you have to know a little about the internals of the family to avoid pitfalls - and to interface to other families. Analog ICs require more understanding. SNIP On the other hand, there is validity in constantly thinking through whether something should be done with transistors or ICs. Or with a $2 microcomputer. IMO, evaluating the trade-off between hardware and software is just as important. Where should one draw the line? My hobby RF experience has mostly been limited to VHF frequency converters. OTOH I assembled the first FM-stereo broadcast station in the Washington DC area, WHFS 102.3 MHz. The "components" were rather large: an HH Scott stereo generator, an RCA "iron fireman" FM exciter, and a 1 kW power power amplifier that had seen service a number of other places. I built a frequency-multiplier / IPA between the exciter and the 4-400 finals, and the power supplies including that for the finals. I built the stereo audio console for the station; my memory is a little hazy after 40 years, but I think the console used some audio ICs. SNIP But these are design decisions, not some rhetoric about how everything must be made from scratch. Any time something is designed, it's important not just to look at the way to do it, but at other alternatives, because people often do get blocked by looking down only one path. As someone else said, engineering is making what you want from the parts that are available. 73 de bob w3otc |
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