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#1
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Jim wrote:
I recently won a HOMEBREW 23 channel CB receiver. Yes I know it's not a real boatanchor but given that it has 11 tubes plus several diodes , I thought I'd ask about it here. It looks very well made. I was hoping that some one would recognize it by tube line up. I just looked at it and haven't started drawing the schematic yet. It has the following tubes, 6EH7 (the RF amp) , 12AT7, 12AU7, 6BN8, 6HR6, 6BA6, 6BE6, 6GX6, 12AX7, 6AQ5, and an OA2. It has 6 RF and IF transformers. The antenna is connected directly to a transformer with the RF amp feed by a cap off the secondary. The first oscillator(?) Uses a 29305 Kc crystal. It has a "S meter" and what I suspect is a meter adj. pot on the back. There is a octal socket on the back labeled transmitter that has two lines jumped as well as a voltage divider with a large electrolytic to ground in the middle of the divider. The tuning cap is three section with one section switched by a control on the front panel. The tuning cap is driven by a very nicely home made dial cord mechanism with a heavy flywheel. So far I have figured out the RF and audio gain controls. The other two front panels pots function are a question as well as the functions of four multi section toggle switches. With the filter caps being bad. I have not powered it up for more than two minutes. Does anyone remember a home brew rig with these features HAM or CB? I would like to find a schematic if possible. I looked at the HBR site and it doesn't seem to match anything there. But given the limited 23 channel coverage plus channels A-D it looks like it's from the late 1960's or real early 1970's . Thanks Jim Jim, I'm very surprised to hear that someone would homebrew a CB rig: I'd guess it's a commercial unit without the front plate unless the workmanship is definitely "homebrew". The mixer crystal is a puzzle: it implies an IF in the ~3.3MHz range, which I've never seen before. OTOH, if it was made for 10 Meter ham use, a 29.305 MHz crystal and a 455 KHz IF would work out to either 29.760 or 28.850 MHz, and only the lower frequency is in the 10 meter band. It might have been a custom-made unit for CAP or other use on 29.76, but I don't have any experience with those. I'm going to guess that you have a CB set that was modified for either 10 meter ham use or for some quasi-government use on 29.76. HTH. William (Filter noise from my address for direct replies) |
#2
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William Warren ") writes:
Jim wrote: I recently won a HOMEBREW 23 channel CB receiver. Yes I know it's not a real boatanchor but given that it has 11 tubes plus several diodes , I thought I'd ask about it here. It looks very well made. I was hoping that some one would recognize it by tube line up. I just looked at it and haven't started drawing the schematic yet. It has the following tubes, 6EH7 (the RF amp) , 12AT7, 12AU7, 6BN8, 6HR6, 6BA6, 6BE6, 6GX6, 12AX7, 6AQ5, and an OA2. It has 6 RF and IF transformers. The antenna is connected directly to a transformer with the RF amp feed by a cap off the secondary. The first oscillator(?) Uses a 29305 Kc crystal. It has a "S meter" and what I suspect is a meter adj. pot on the back. There is a octal socket on the back labeled transmitter that has two lines jumped as well as a voltage divider with a large electrolytic to ground in the middle of the divider. The tuning cap is three section with one section switched by a control on the front panel. The tuning cap is driven by a very nicely home made dial cord mechanism with a heavy flywheel. So far I have figured out the RF and audio gain controls. The other two front panels pots function are a question as well as the functions of four multi section toggle switches. With the filter caps being bad. I have not powered it up for more than two minutes. Does anyone remember a home brew rig with these features HAM or CB? I would like to find a schematic if possible. I looked at the HBR site and it doesn't seem to match anything there. But given the limited 23 channel coverage plus channels A-D it looks like it's from the late 1960's or real early 1970's . Thanks Jim Jim, I'm very surprised to hear that someone would homebrew a CB rig: I'd guess it's a commercial unit without the front plate unless the workmanship is definitely "homebrew". IN the sixties (and early seventies), it was common for the hobby electronic magazines to treat CB as a hobby. This was especially so for "Electronics Illustrated" that had quite a few construction articles, going from simple to quite sophisticated. So you could build a panadaptor to check out the adjacent channels, and a receiver to monitor channel 9 (when it became a designated emergency channel) and even a grid dip oscillator for "Class E CB" up at 220MHz, even though that service never came to pass. THere is nothing unique about the description. I can't recall seeing much in just tuneable CB receivers in the hobby magazines from that time, but it sounds like a relatively generic receiver (and he did say receiver, not transceiver). If it is a CB receiver, there's nothing to guarantee that it was built from a description in a magazine article, or that it's a direct copy of something. Someone could have made it up, or copied something else with mods for CB. Afterall, no matter what the unit is, someone has to create a unit before they can write it up in a magazine, so something can exist without a magazine writeup. And given that he says it's a receiver, if it was a commercial unit the pickings are slim. I can think of only one manufacturer that made a standalone CB receiver. Michael VE2BVW |
#3
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On Apr 19, 9:28 am, (Michael Black) wrote:
IN the sixties (and early seventies), it was common for the hobby electronic magazines to treat CB as a hobby. This was especially so for "Electronics Illustrated" that had quite a few construction articles, going from simple to quite sophisticated. In the early sixties I ordered one of those cb kits from an electronics magazine. It consisted of a crudely punched chassis, a bag of parts and a schematic. I never did get it to work. |
#4
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cmdr buzz corey wrote:
On Apr 19, 9:28 am, (Michael Black) wrote: IN the sixties (and early seventies), it was common for the hobby electronic magazines to treat CB as a hobby. This was especially so for "Electronics Illustrated" that had quite a few construction articles, going from simple to quite sophisticated. In the early sixties I ordered one of those cb kits from an electronics magazine. It consisted of a crudely punched chassis, a bag of parts and a schematic. I never did get it to work. I thought building a kit CB transceiver was illegal due to the type acceptance issue? --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#5
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Scott Dorsey ) writes:
cmdr buzz corey wrote: On Apr 19, 9:28 am, (Michael Black) wrote: IN the sixties (and early seventies), it was common for the hobby electronic magazines to treat CB as a hobby. This was especially so for "Electronics Illustrated" that had quite a few construction articles, going from simple to quite sophisticated. In the early sixties I ordered one of those cb kits from an electronics magazine. It consisted of a crudely punched chassis, a bag of parts and a schematic. I never did get it to work. I thought building a kit CB transceiver was illegal due to the type acceptance issue? Certainly Heathkit got around the issue with their full blown CB set(s) by having the transmitter arrive as a preassembled module. But I thought there was a CB "Benton Harbor Lunchbox" for a while, and I can't imagine they would have a module for such a low end unit. So perhaps the type acceptance came a bit later? I can't remember (not that I was aware of such things at the time, but I have read lots of back issues of magazines). In the very early days, there was equipment being made out of people's garages. So either the rules were more lax then, or from the outside there were companies selling things that weren't legal. Michael VE2BVW |
#6
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On Thu, 19 Apr 2007 17:38:55 +0000, Michael Black wrote:
I thought building a kit CB transceiver was illegal due to the type acceptance issue? .... So perhaps the type acceptance came a bit later? I can't remember (not that I was aware of such things at the time, but I have read lots of back issues of magazines). ISTR: - Heath equipment was acceptable contingent on being assembled according to the instructions. There was a notice in some of the manuals about that - ISTR some devices where one part was a Part 15 label which the builder was to sign & date & stick to the completed kit certifying they'd followed the instructions. - It was legal to homebrew CB gear in the early days of the service, but that rule was changed - well before the 1960s. (I'm not sure it was *ever* legal to homebrew 27MHz CB gear, it may have only been legal for the old 470MHz stuff) |
#7
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Hi,
On Fri, 20 Apr 2007 04:34:00 +0000, Doug Smith W9WI wrote: - It was legal to homebrew CB gear in the early days of the service, but that rule was changed - well before the 1960s. (I'm not sure it was *ever* legal to homebrew 27MHz CB gear, it may have only been legal for the old 470MHz stuff) It may not have been in the US, but before regulation and since deregulation, one can build up to 5 CB's and call them prototypes in .ca land, as long as they meet Industry Canada (then the Department of Communications) specifications. Maybe it's a Canuck rig? Cheers, __ Gregg |
#8
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![]() "Scott Dorsey" wrote in message ... cmdr buzz corey wrote: On Apr 19, 9:28 am, (Michael Black) wrote: IN the sixties (and early seventies), it was common for the hobby electronic magazines to treat CB as a hobby. This was especially so for "Electronics Illustrated" that had quite a few construction articles, going from simple to quite sophisticated. In the early sixties I ordered one of those cb kits from an electronics magazine. It consisted of a crudely punched chassis, a bag of parts and a schematic. I never did get it to work. I thought building a kit CB transceiver was illegal due to the type acceptance issue? --scott -- It may be now, I don't know. At one time Heathkit put out a kit called a CB-1. This was a simple CB and not at all like the one being talked about. There may have been others, but this is one I know of for sure. |
#9
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(Scott Dorsey) writes:
I thought building a kit CB transceiver was illegal due to the type acceptance issue? --scott There was a period, long, long ago, when CB was young, and I was not yet but a leering glance, that building CB gear was okay. It stopped being okay before the explosion of the mid-70s. -- Lawrence Statton - m s/aba/c/g Computer software consists of only two components: ones and zeros, in roughly equal proportions. All that is required is to place them into the correct order. |
#10
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Lawrence Statton wrote:
(Scott Dorsey) writes: I thought building a kit CB transceiver was illegal due to the type acceptance issue? --scott There was a period, long, long ago, when CB was young, and I was not yet but a leering glance, that building CB gear was okay. It stopped being okay before the explosion of the mid-70s. There were a number of kits as I remember. Heath had several, as did Allied (Knight Kits). These could be at least as sophisticated as the mid-range factory units of the day. jak |
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