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On Mon, 23 Feb 2004 16:12:55 -0700, Jim Thompson
wrote: Look up 3rd order intercept point. And pay special attention if this is input IP3 (the power of the test tones are measured at the input of the device) or output IP3 (power levels measured at device output). This is especially important, since a typical active Gilbert cell mixer (1496, NE602) have some gain, while a typical diode ring mixer (SBL-1) have a 6-7 dB loss. Paul OH3LWR |
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Jan-Martin Noeding, LA8AK wrote in message ... On Mon, 23 Feb 2004 16:12:55 -0700, Jim Thompson wrote: It's only an "uncommon abbreviation" to certain Brits who think they can learn by insulting the masters ;-) Look up 3rd order intercept point. ...Jim Thompson thought everybody had studied Ham Radio December 77 throughly - even in UK..... 73 ex-G5BFV (at BPO radio station Bearley/SOA) ---- Jan-Martin, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/ That's a helluva web site you keep there :-) Impressive! regards john |
Jan-Martin Noeding, LA8AK wrote in message ... On Mon, 23 Feb 2004 16:12:55 -0700, Jim Thompson wrote: It's only an "uncommon abbreviation" to certain Brits who think they can learn by insulting the masters ;-) Look up 3rd order intercept point. ...Jim Thompson thought everybody had studied Ham Radio December 77 throughly - even in UK..... 73 ex-G5BFV (at BPO radio station Bearley/SOA) ---- Jan-Martin, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/ That's a helluva web site you keep there :-) Impressive! regards john |
"W3JDR" wrote in message ... Take a look at Analog Devices' line of DDS chips. Pretty much a one-chip (needs ucontroller to drive it) digital solution to turn your 10MHz clock into virtually any frequency below 5 MHz (in theory; below 4MHz in easy practicality). The AD9834 only consumes 20mw at 3.3 VDC. There are many other devices in the product line. Many have built-in comparators to produce square-wave output. Joe W3JDR Joe, I'd gladly use the Analog Devices DDS chips if they offered them in something other than a SadoMasochistic Device (SMD) package. It's a darn shame they can't make a limited run (say 10k) of some of these chips in a PDIP package for hams and other r.f. experimenters. If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP packaged version sells for about $6, I think) , I'd buy a dozen for various projects, but in the tiny SMD package they're nothing but useless to me. I'm new to the newsgroup and am sure that this is not the first gripe about SMD's, but I refuse to use them - not because I can't (at least not yet), but because I don't want to endure the angst. -- Chip KC5UES real E-mail Address: -----= 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! =----- |
"W3JDR" wrote in message ... Take a look at Analog Devices' line of DDS chips. Pretty much a one-chip (needs ucontroller to drive it) digital solution to turn your 10MHz clock into virtually any frequency below 5 MHz (in theory; below 4MHz in easy practicality). The AD9834 only consumes 20mw at 3.3 VDC. There are many other devices in the product line. Many have built-in comparators to produce square-wave output. Joe W3JDR Joe, I'd gladly use the Analog Devices DDS chips if they offered them in something other than a SadoMasochistic Device (SMD) package. It's a darn shame they can't make a limited run (say 10k) of some of these chips in a PDIP package for hams and other r.f. experimenters. If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP packaged version sells for about $6, I think) , I'd buy a dozen for various projects, but in the tiny SMD package they're nothing but useless to me. I'm new to the newsgroup and am sure that this is not the first gripe about SMD's, but I refuse to use them - not because I can't (at least not yet), but because I don't want to endure the angst. -- Chip KC5UES real E-mail Address: -----= 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! =----- |
If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP
packaged version sells for about $6, I think) , I'd buy a dozen for various projects, but in the tiny SMD package they're nothing but useless to me. I'm new to the newsgroup and am sure that this is not the first gripe about SMD's, but I refuse to use them - not because I can't (at least not yet), but because I don't want to endure the angst. Sounds like a good opportunity for an enterprising ham - fab up a bunch of adapter boards (or buy 'em premade - I think Ares has something like this), solder down the SMD parts, and sell the resulting PDIP-compatible boards to interested homebrewers. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP
packaged version sells for about $6, I think) , I'd buy a dozen for various projects, but in the tiny SMD package they're nothing but useless to me. I'm new to the newsgroup and am sure that this is not the first gripe about SMD's, but I refuse to use them - not because I can't (at least not yet), but because I don't want to endure the angst. Sounds like a good opportunity for an enterprising ham - fab up a bunch of adapter boards (or buy 'em premade - I think Ares has something like this), solder down the SMD parts, and sell the resulting PDIP-compatible boards to interested homebrewers. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Chip,
I totally agree with you about the difficulty in handling fine-pitch SMD parts. It's a sign of the times. FYI, check out the DDS Daughterboard at www.njqrp.org. This is a DDS application board kit with on-board clock oscillator (you could run it from an external oscillator if you wish). There's also a link to a service that will solder your DDS chip to your bare board for $6 in single quantities. Joe W3JDR "ChipS" wrote in message ... "W3JDR" wrote in message ... Take a look at Analog Devices' line of DDS chips. Pretty much a one-chip (needs ucontroller to drive it) digital solution to turn your 10MHz clock into virtually any frequency below 5 MHz (in theory; below 4MHz in easy practicality). The AD9834 only consumes 20mw at 3.3 VDC. There are many other devices in the product line. Many have built-in comparators to produce square-wave output. Joe W3JDR Joe, I'd gladly use the Analog Devices DDS chips if they offered them in something other than a SadoMasochistic Device (SMD) package. It's a darn shame they can't make a limited run (say 10k) of some of these chips in a PDIP package for hams and other r.f. experimenters. If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP packaged version sells for about $6, I think) , I'd buy a dozen for various projects, but in the tiny SMD package they're nothing but useless to me. I'm new to the newsgroup and am sure that this is not the first gripe about SMD's, but I refuse to use them - not because I can't (at least not yet), but because I don't want to endure the angst. -- Chip KC5UES real E-mail Address: -----= 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! =----- |
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