Fox Victor Forty Meter Transverter Redux

The Fox Victor Forty Revisited: How I really got started Homebrewing

by Ramon R. Reyes DU1FV BSEE UP 77

In the 80's I used to for an engineering geoscience company in Legaspi Village, Makati. I was in the seismometer and telemetry department. I owe that small company for my first intro to computers through the ($10,000.00 back, then) OKITAC 4300 computer that used magnetic memory, front cpu panel bit-key programming and paper tape for data storage and a modified teletype for a printer! (As the 90's, I have been told you could get this computer surplus in Akihabara quite cheaply.)

One part of the daily office commute I really look forward to was dropping by a small shop on Pasay Road where I often saw Japanese ham radio magazines displayed on its window. They are used. Probably the owner of the store is a Japanese ham. The full color radio ads were really nice and I manage to make a little sense out of most circuit drawings so that was good enough reason for me to buy. I managed to save up some of my left-over lunch money to buy a copy every now and then. Over a couple of years, I managed to acquire a collection of about five magazines before the shop closed.

On one day I saw this cover. My poor Japanese told me it was a “10Mhz band”--themed edition. I believe it was just about the time the new WARC bands were opened in JA. Inside were a lot of articles about the new band, its propagation characteristics, mods for existing radios to enable it, etc but what interested me was one about constructing a transverter for operating in this new band.

Here are some scans of that 10Mhz Transverter article. I am afraid the first page of the article is now missing. Please pardon the wear and tear but that will show you the amount of time I spent pouring over it. I had put in some blue and red ink annotations.

These are the circuit layout diagrams.  The left portion is the receive section and transmit portion is on the right. Dead bug construction is used on a copper clad board.

These show the schematics.

The block diagram of the system and a photo of the transmit section on top.

It was this article that gave me the idea of making a transverter but one that takes a 27mhz signal (not a 28mhz one) and puts out a 7mhz signal (instead of a 10mhz signal)!  I felt the source and target frequencies were near enough that of the original article, that it was worth a try to use similar circuitry.

A few days ago, as I was cleaning up the library, I found some old manuscripts of an article that Rudy Rojas ex DU1RF who edited the PARA publication back then, asked me to write. I did not have a pc or a printer then, just an old Underwood. I just did some minor editing of the scans to re-position the drawings.

Much later on, I found a source for that double balanced mixer used in the original Japanese article and adopted that instead of the Mosfet mixer in subsequent experiments with improved results. I was buying some parts in Earl Hornbostel's (now SK) store (when it was still near the now defunct Waterous hospital, when I notice a flyer pasted on the wall about an “SBL-1” being available. I snapped up a piece at that instant, I recall.
The SBL-1 found use in a 4-band hf transverter that I made for a six meter Icom transportable rig, the IC-505. 

 I departed from the original Japanese article in that I used just one oscillator circuit (per band) and just one double balanced mixer to save on money but that produced more complexity  in the diode switching circuitry. But that is another story!

Allow me to give credit to Rudy Rojas ex DU1RF (member : MARS) for inspiring me to write my first article in the PARA publication. I do not know his present whereabouts. The last I heard was that he has moved to Pagadian City where he operates a printing company.  I hope he is well. DU1JIC mentioned in the manuscript is now and has been for many years DU1ANV (Joe).  Bob DU9BA, I believe is well.  I saw his relatively in maintained fb page.  To my knowledge, he  has left amateur radio but not without imparting a big influence on our ham radio outlook.

Well, let me re-iterate that by no means is this a construction article. It is more of a story on my start in homebrewing radio gear. Maybe one day I will get to write a proper construction article. Email me if you have any questions at mondu1fv atsign yahoo dot com.