MYSTERY HOMEBREW TRANSMITTER - Does anyone recognize this?

Just what it says -- this is the place for any discussions not related to Buying, Selling and Trading ham gear. The discussion must be related to Ham Radio.
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ve6ne
Posts: 6
Joined: Wed Apr 13, 2005 8:04 pm

MYSTERY HOMEBREW TRANSMITTER - Does anyone recognize this?

Post by ve6ne »

I picked up this H/Brew TX a while ago, and wonder if anyone can identify its source, i.e.--type, schematic info, if it came from an ARRL publication, etc. I´m not too bright on these things so need all the help I can get. And, it even works! It was constructed by a well known radio dealer (now an S/K) and most likely was done back in the 60s or 70s.

11 Tube Complement:

6146 (2), 5763 (2), 0C3W (2), 12AU7, 6AU6, 12BH7, 12AX7, 6AQ5

Thanks kindly. ...Wayne...

I will figure out how to source these images here if it kills me so hang in there :?
http://members.shaw.ca/wlrviking/mysteryTX-1.jpg
http://members.shaw.ca/wlrviking/mysteryTX-2.jpg
http://members.shaw.ca/wlrviking/mysteryTX-3.jpg
http://members.shaw.ca/wlrviking/mysteryTX-4.jpg
http://members.shaw.ca/wlrviking/mysteryTX-5.jpg
http://members.shaw.ca/wlrviking/mysteryTX-6.jpg
http://members.shaw.ca/wlrviking/mysteryTX-7.jpg
http://members.shaw.ca/wlrviking/mysteryTX-8.jpg
WA9WVX
Posts: 103
Joined: Tue Aug 09, 2005 2:31 am
Location: QRZ Indicates Northern Illinois

Home Brew Transmitter

Post by WA9WVX »

I looked in my 1965 and 1977 ARRL Handbook but could not find a transmitter design like the one you have posted. As a suggestion since you feel the design came from an ARRL article .... maybe even one of their QST magazines during the late 1960s or into the early 1970s being tube technology. You might consider doing some research at a local library for the ARRL Handbooks 1966 through 1975 and even the QST magazines for the same years. I'm taking a wild guess that the transmitter was AM and CW because of the two 5673 driving a pair of 6146 Finals. I think the 5763s were used as Modulators.

The person who built this unit did excellence workmanship on the construction techniques of this transmitter. It looks so good being homebrew, it could have passed as a commercially built unit. The transmitter was a labor of love while the now Silent Key put forth the effort.
ve6ne
Posts: 6
Joined: Wed Apr 13, 2005 8:04 pm

Post by ve6ne »

Many thanks for the comments....I was beginning to give up the hope of any replies. But I agree with your comments, and have looked through a few of the articles from that era, being between 1955 and 1972 when I think it syncs with this technology. I am hardly an appropriate "expert" on that though! The VFO is suspiciously similar to the Heath VF-1, or at least the front panel is. It certainly looks like a "blend" of several different construction articles, i.e. the
VFO probably is one article; the power supply stolen from somewhere else; and the RF final a copy of something else, being close to the final RF stage of the Hallicrafters HT37 which was popular during that era since it used a similar twin 6146B RF stage. A nice piece of work nontheless, and not sure what I will do with it since I have more boatanchors than space to put them in. :) Again, thanks kindly for the feedback....it is most appreciated.
WA9WVX
Posts: 103
Joined: Tue Aug 09, 2005 2:31 am
Location: QRZ Indicates Northern Illinois

Mystery H/B XMTR

Post by WA9WVX »

Reading your original post again and your reply on this Mystery H/B Transmitter seems to fill in the missing information. Since the Silent Key was a well known radio dealer, he probably did have access to many radio equipment manufacture's schematic designs. Then took what he wanted from each design incorporating all into his H/B package. This would have been very clever 8) on his part since he was not manufacturing multiple units for sale on the market.

In the past, many manufactures would purchase the competition's product through their network of sales channels. Then their sales personnel would bring the units with schematics back the company for their product development engineers to review and studying what they were interested in but not copying for patent reasons being the Greenback $$$$$$$ Dollars to the company that holds the patent and/or Lawsuits. And then incorporating their own circuit designs. :roll:

Many of the early Amateur Radio designs were incorporated into commercially manufactured radio equipment being for the Amateur and/or Commercial Land Mobile Radio Markets. This still exist today but mostly in the written Software code languages. And "IF" the corporation is big enough, with deep financial pockets, they"ll buy out the competition taking what they want, down sizing the development personnel and outsouring to a third world country. :(
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