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Radio conversion
Season`s greetings to all...
While in England in `91, I picked up a Ford motor car radio receiver. P21 79GB-18K810 HA . Two band , LW & MW .. (166 KHz - 285 KHz LW & 666KHz - 1500Khz MW +/- ) .I would like to extend the LW band as high in frequency as i can , and the MW band as low as i can in frequency..I.F. is 465 kHz...Object : To create a beacon ( 200KHz - 400 KHz ) receiver... Is there anyone out there that has any experience , and or ideas with what i have in mind ? TIA Gene WB7NGI |
Radio conversion
On Dec 27, 1:34*pm, Gene wrote:
Season`s greetings to all... While in England in `91, I picked up a Ford motor car radio receiver. P21 79GB-18K810 *HA . * Two band , LW & MW .. (166 KHz - 285 KHz LW & *666KHz *- 1500Khz MW *+/- ) .I would like to extend the LW band as high in frequency as i can , and the MW band as low as i can in frequency..I.F. is 465 kHz...Object : To create a beacon ( 200KHz - 400 KHz ) receiver... Is there anyone out there that has any experience , and or ideas with what i have in mind ? TIA * Gene * WB7NGI If analog tuning then you add or remove capacitance to each LC and hope that the padding can be adjusted or supplemented enough so that everything (mixer and front end) tracks. It won't be so much "extending" the tuning range but instead will be "shifting" the tuning range. If digital tuning then you'll have to locate the schematic for the PLL chipset and see if you can convince the local oscillator to shift far enough. With some PLL chipsets there are programming pins or diodes that set the allowed range. In many cases, if you don't need the original tuning range, you can patch in a divide by two or just change the reference oscillator. If you change the reference oscillator then the display won't be right but will be mathematically related to the actual frequency. I collect British tabletop radios and am quite familiar with their longwave dial on tube-type analog sets (my favorite is when they do not list frequencies but only wavelengths) but am not particularly familiar with British car radios. My one piece of advice with respect to car radios from foreign autos of 70's vintage or older, is to check carefully WRT 6V or 12V and WRT to negative ground or positive ground. Tim N3QE |
Radio conversion
On Dec 28, 12:38�pm, Tim Shoppa wrote:
On Dec 27, 1:34�pm, Gene wrote: Season`s greetings to all... While in England in `91, I picked up a Ford motor car radio receiver. P21 79GB-18K810 �HA . � Two band , LW & MW .. (166 KHz - 285 KHz LW & �666KHz �- 1500Khz MW �+/- ) .I would like to extend the LW band as high in frequency as i can , and the MW band as low as i can in frequency..I.F. is 465 kHz...Object : To create a beacon ( 200KHz - 400 KHz ) receiver... Is there anyone out there that has any experience , and or ideas with what i have in mind ? TIA � Gene � WB7NGI If analog tuning then you add or remove capacitance to each LC and hope that the padding can be adjusted or supplemented enough so that everything (mixer and front end) tracks. It won't be so much "extending" the tuning range but instead will be "shifting" the tuning range. If digital tuning then you'll have to locate the schematic for the PLL chipset and see if you can convince the local oscillator to shift far enough. With some PLL chipsets there are programming pins or diodes that set the allowed range. In many cases, if you don't need the original tuning range, you can patch in a divide by two or just change the reference oscillator. If you change the reference oscillator then the display won't be right but will be mathematically related to the actual frequency. I collect British tabletop radios and am quite familiar with their longwave dial on tube-type analog sets (my favorite is when they do not list frequencies but only wavelengths) but am not particularly familiar with British car radios. My one piece of advice with respect to car radios from foreign autos of 70's vintage or older, is to check carefully WRT 6V or 12V and WRT to negative ground or positive ground. Tim N3QE Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , will have to do some reverse engineering to to figure out what cap , is what Thanks , Gene WB7NGI |
Radio conversion
On Dec 29, 8:38*pm, Gene wrote:
Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE |
Radio conversion
Tim Shoppa wrote:
On Dec 29, 8:38 pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE Í guess by about 1990 (20 years ago) they had all abandoned the slug-tuned stages. I had a '90 era car radio found in the Caribbean. It locked onto the 9kc European channels. I'm sure there was some chip jumpering that would allow tuning to American 10kc channels but I never could find the info. |
Radio conversion
On Dec 29 2009, 10:00*pm, Tim Shoppa wrote:
On Dec 29, 8:38*pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE |
Radio conversion
Hey OM:
The only way to make that work is with a converter. Back in the day before police scanners, I made a converter that converted the 70cm police band down to the AM broadcast band. 530Khz thru 1600Khz was the band back then. My converter could put 3 local police frequencies on the AM band. All the converter is is an LO, input tank circuit, and a mixer. The only active component was the LO. I used a CB rock which were dirt cheap. Caught the 70cm harmonic into the mixer, getting the police band down to the AM band. I made a version that plugged inline with the car antenna and the car radio, that could be switched in and out. I couldn't make enough of them, Was the best selling product I ever made. 73 OM de n8zu On Jan 5, 5:17*pm, joeturn wrote: On Dec 29 2009, 10:00*pm, Tim Shoppa wrote: On Dec 29, 8:38*pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another *varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE |
Radio conversion
On Jan 7, 10:38*am, raypsi wrote:
Hey OM: The only way to make that work is with a converter. Back in the day before police scanners, I made a converter that converted the 70cm police band down to the AM broadcast band. 530Khz thru 1600Khz was the band back then. My converter could put 3 local police frequencies on the AM band. All the converter is is an LO, input tank circuit, and a mixer. The only active component was the LO. I used a CB rock which were dirt cheap. *Caught the 70cm harmonic into the mixer, getting the police band down to the AM band. I made a version that plugged inline with the car antenna and the car radio, that could be switched in and out. I couldn't make enough of them, Was the best selling product I ever made. 73 OM de n8zu On Jan 5, 5:17*pm, joeturn wrote: On Dec 29 2009, 10:00*pm, Tim Shoppa wrote: On Dec 29, 8:38*pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another *varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE- Hide quoted text - - Show quoted text - Raypsi You cant find the specs on a converter anymore! I probably used one of your gadgits back in the 70s, the car am radio was converted to cb band! My titan 4 reciever had a trimmer just above the vfo to zero its frequency with the dial reading! I simply put the trimmers center point to a toggle switch that led to two other varible capacitors and could go up or below the cb band, tuning each to a specified value! I would love to be able to get a converter to fill in the gaps on a ubc 780 xlt. A converter to allow it to start at 100 hz and go to 4 gigs will be your next best seller without having to use the pc software;) |
Radio conversion
raypsi wrote:
Hey OM: The only way to make that work is with a converter. Back in the day before police scanners, I made a converter that converted the 70cm police band down to the AM broadcast band. 530Khz thru 1600Khz was the band back then. My converter could put 3 local police frequencies on the AM band. All the converter is is an LO, input tank circuit, and a mixer. The only active component was the LO. I used a CB rock which were dirt cheap. Caught the 70cm harmonic into the mixer, getting the police band down to the AM band. I made a version that plugged inline with the car antenna and the car radio, that could be switched in and out. I couldn't make enough of them, Was the best selling product I ever made. 73 OM de n8zu On Jan 5, 5:17 pm, joeturn wrote: On Dec 29 2009, 10:00 pm, Tim Shoppa wrote: On Dec 29, 8:38 pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE How did that work? Wasn't the police band using FM back then like they do today? I suppose the RF signal may have had enough "AM" component perhaps? |
Radio conversion
"Scott" wrote in message ... raypsi wrote: Hey OM: The only way to make that work is with a converter. Back in the day before police scanners, I made a converter that converted the 70cm police band down to the AM broadcast band. 530Khz thru 1600Khz was the band back then. My converter could put 3 local police frequencies on the AM band. All the converter is is an LO, input tank circuit, and a mixer. The only active component was the LO. I used a CB rock which were dirt cheap. Caught the 70cm harmonic into the mixer, getting the police band down to the AM band. How did that work? Wasn't the police band using FM back then like they do today? I suppose the RF signal may have had enough "AM" component perhaps? It is easy to detect FM on an AM radio by using slope detection. Not the best way, but it works. http://www.tpub.com/neets/book12/51c.htm |
Radio conversion
Hey OM:
Yeah, a converter to gets the blocked cell phone bands. They making those things in some ones garrage in Hong Kong. Naw the top selling device would be a cell phone jammer. Flick it on and all the cell phones within a certain radius go down. A jammer would be highly illegal though, even a police converter nowadays would be the same: illegal. 73 OM de n8zu On Jan 5, 5:17*pm, joeturn wrote: On Dec 29 2009, 10:00*pm, Tim Shoppa wrote: On Dec 29, 8:38*pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another *varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE- Hide quoted text - - Show quoted text - Raypsi You cant find the specs on a converter anymore! I probably used one of your gadgits back in the 70s, the car am radio was converted to cb band! My titan 4 reciever had a trimmer just above the vfo to zero its frequency with the dial reading! I simply put the trimmers center point to a toggle switch that led to two other varible capacitors and could go up or below the cb band, tuning each to a specified value! I would love to be able to get a converter to fill in the gaps on a ubc 780 xlt. A converter to allow it to start at 100 hz and go to 4 gigs will be your next best seller without having to use the pc software;)- Hide quoted text - - Show quoted text - |
Radio conversion
On Jan 8, 9:11*am, raypsi wrote:
Hey OM: Yeah, a converter to gets the blocked cell phone bands. They making those things in some ones garrage in Hong Kong. Naw the top selling device would be a cell phone jammer. Flick it on and all the cell phones within a certain radius go down. A jammer would be highly illegal though, even a police converter nowadays would be the same: illegal. 73 OM de n8zu On Jan 5, 5:17*pm, joeturn wrote: On Dec 29 2009, 10:00*pm, Tim Shoppa wrote: On Dec 29, 8:38*pm, Gene wrote: Tim, thanks for the reply...analog...made in Canada....so i assume it is a Philco-Ford , unable to find schematic , *will have to do some reverse engineering to to figure out what cap , is what Internally most of the good AM car radios I've met had mechanically ganged slug tuning, although variable capacitor tuning existed too. I once broadened the band of a Titan 4 reciever by adding a varible capacitor with a spst it might need another *varible capacitor with a spdt to get the other end of the spectrum. That's great if you're comfortable adjusting the mechanics of the radio internally to get the tracking right. Remember, you won't be broadening the tuning range, you'll be shifting the tuning range. Tim N3QE- Hide quoted text - - Show quoted text - Raypsi You cant find the specs on a converter anymore! I probably used one of your gadgits back in the 70s, the car am radio was converted to cb band! My titan 4 reciever had a trimmer just above the vfo to zero its frequency with the dial reading! I simply put the trimmers center point to a toggle switch that led to two other varible capacitors and could go up or below the cb band, tuning each to a specified value! I would love to be able to get a converter to fill in the gaps on a ubc 780 xlt. A converter to allow it to start at 100 hz and go to 4 gigs will be your next best seller without having to use the pc software;)- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - No the police bands are wide open they dont use digital because of the range. They all still use analog because of its dependability! They do use cell phones to communicate privately on digital,but theirs still that problem of 40 kz between transmit and recieve to over come. That only got you a dependent pimp or drug dealer.The cordless phones are still of interest however,the scanners that can get into the 2-4gigs are too expensive for the ordinary joeI;-) |
Radio conversion
PS
The authorities/military are the only ones that have a need to jam RF (a cell phone) but those are all ready furnished them! http://www.sesp.com/ |
Radio conversion
highlandham wrote:
99% of all the cordless phones are now digital (mostly 900MHz) Many are of the DECT type (Digitally Enhanced Communication Technology) Those cordless phones which are GAP compatible (even when from different manufacturers) can be used with the same base station (unit wired to the telephone system) Maybe in the US they are. In the rest of the world, and many sold in the US, use the 1.8gHz band. The low end of the US 1.9gHz band overlaps the high end of the 1.8gHz band used elsewhere, so they can be 1.8 gHz here and 1.9 gHz there. :-) There are some 2.4gHz cordless phones, but AFAIK they are slowly being phased out because the poorly designed ones interfere with WiFi, and the good ones that look for a clear channel can't function in a heavy WiFi environment. 5.8gHz phones, only legal in the Americas, are similar to their 2.4 gHz cousins and eventually as the 5.8gHz gets taken over by 802.11n networks, they too will disapear. BTW, GAP phones are not always useable with other base stations. In order to access a base station a handset must register with it, and currently that has to be done by placing both the handset and base station in registration mode and inserting the handset into the base station. Works in theory, but every manufacturer uses a different base design and they contacts won't mate. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. |
Radio conversion
We now have a 6.2 ghz cordless! Digital cell phones are only good to
reach the nearest microwave tower then then the signal is relayed! This is most likely the way the Europeans use digital as it's no good over a distance of 30 miles without being relayed. The only bennifit of digital is a weak signal demanding cable or satellite subscriptions$$$$ To amplifi the digital signal enough to be usable at greater distances will have a domino effect on its technology of being deadly due to exposure to microwaves to the human brain and redering one impotent! http://www.articlesbase.com/technolo...se-413085.html This release of harmful cellphone use will hurt the industry or do away with it completely!! $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ |
Radio conversion
The Government once conducted a study of the possibility of RF being
harmful but conviniently the results were altered! Here's a better read for cellphone's harmful effects! http://www.infowars.com/cell-phone-u...ful-to-unborn/ but mega biz has no feelings where loss of revenue is concerned, they just lobby in what ever brings the biggest buxI;-) |
Radio conversion
Geoffrey S. Mendelson wrote:
BTW, GAP phones are not always useable with other base stations. In order to access a base station a handset must register with it, and currently that has to be done by placing both the handset and base station in registration mode and inserting the handset into the base station. Works in theory, but every manufacturer uses a different base design and they contacts won't mate. There is no "inserting in the base station" during registration of a handset with a base station. You only select some function, key-in some number, and press some button. My base station does not even have the facility to charge a handset, there is a separate charger base for that. |
Radio conversion
highlandham wrote:
In Britain the police is now on a digital nation wide trunking system ,originally called Tetra ; I believe it is a Motorola system . The Ambulance- and other public services are gradually also adopting the system ,which eventually will be pan-european . In the Netherlands it has been active for several years already. There is no more police radio snooping using FM scanners anymore. (of course this means the public cannot serve as an extra eye and ear to the police anymore, either) |
Radio conversion
On Dec 27 2009, 3:34*pm, Gene wrote:
Season`s greetings to all... While in England in `91, I picked up a Ford motor car radio receiver. P21 79GB-18K810 *HA . * Two band , LW & MW .. (166 KHz - 285 KHz LW & *666KHz *- 1500Khz MW *+/- ) .I would like to extend the LW band as high in frequency as i can , and the MW band as low as i can in frequency..I.F. is 465 kHz...Object : To create a beacon ( 200KHz - 400 KHz ) receiver... Is there anyone out there that has any experience , and or ideas with what i have in mind ? TIA * Gene * WB7NGI Based on the OP. Postulating some numbers! The Long Wave band 166 to 285. That's ratio of 1:1.7 The local oscillator with an IF of 465 would be (465 + 166 = 631) to (465 + 285 = 750) a ratio of only 1:1.18! The Medium Wave band 666 to 1500. A ratio of 1:2.25 The local oscillator being (465 + 666 = 1131) to (465 + 1500 = 1965) a ratio of 1:1.73. To tune 200 to 400 khz. is a ratio of (at least) 1:2. And retaining an IF of 465 would require, say, a local oscillator variation from (465 + 200 = 665) to (465 + 400 = 865) a ratio of 865/665 or 1:1.3 However those 200 to 400 kilohertz aircraft beacon radios, covering specifically 200 to 400 are quite often on eBay! Another alternative would be a 190 to 550 kilo hertz ARC-5/BC453 'Command radio'. Those have 12 volt tubes that can easily be rewired from 24 to 12 volt operation. Another quicker alternative would be some form of small solid state converter tuned or fixed into the Med. Wave band. |
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