My 1975 Tram D201 & VFO

It is amazing what you see on ebay and think “I always wanted one of those!” Not quite as sophisticated as an amateur radio external VFO but the price in some way compensated.Siltronix-VFOs

Well the price was low for a pretty good looking VFO that I thought would work well on an original Bengal Base 23 CH# SSB to get it up on 40 Channels.

Nearly did not buy it as the seller was a pain on the freight cost which was more than double the VFO cost of around $50.!! The aussie dollar makes it worse also! 

But I had a Tram D201 that I had given to a tech a year or so previously to geta few bugs ironed out. The USB / LSB selector was faulty and the performance was not up to what it should be for a great old valve CB Base transceiver that has great reviews online when in optimum condition.

Finally I got lucky when he gave it to another tech Adrian who I have known forever and has always solved tricky problems on my CPI cb radios over the years.

After Adrian had done some expensive but reasonable priced magic on it, I went to his new place and picked it up from him cause its a monster and hard to ship. It is amazing when I bought it from USA ebay it got here in one piece with no parts floating inside like the valves in my DAK MKIX!! But it was a great buy and in great condition considering it was built in 1975. Lucky it was a one owner sold to me by him and in great cosmetic shape. I dont understand how some people treat their radios letting them deteriorate over the years. 

P1030328ssBut the limiting factor for the Tram D201 valve powered CB Base is the 23 xtal locked channels.

As an avid Sidebander for forty years I needed the full 40 Channels to chase decent in band skip especially on CH#38LSB the popular US DX call channel. The Siltronix VFO was the obvious solution to this issue on the D201.

Of course it had to have the correct frequency output to mix with the Tram Xtals to create the band span on the VFO correctly which needed to be at 16MHz. The VFO unfortunately put out 9MHz! OK so to modify the VFO output needed some figuring out which took a few days to do by working through what was generating the output frequency and varying it by some means.

There are various models of the Siltronix VFO’s for many different makes and models of CB radios producing the correct frequencies for operation, so I guessed it must be possible to achieve the right 16 MHz frequency output somehow.


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