RACAL Receivers

An excellent RACAL page may be seen at:

http://www.camuw.demon.co.uk/web_site/g3ynh/Racal/ra17.html

This is a RACAL RA17C-12. It is one of the BEST tube receivers I own. I have to say 'one of' because of my R-390-A... which has been completely restored by Chuck Rippel (see it at: <http://www.n4xy.com/rcvr_MIL_r-390-a_p1.html>.) I don't know how I could choose between the two-and fortunately I have never had to.

Several years ago, I saw an ad for it somewhere. It was in "best offer" form. I knew my funds were such that my 'best offer' wasn't all that 'best'. But I answered immediately anyway, and made certain that the seller understood that I buy things like this to keep, and have a sort of 'rotational' rig policy: I rotate through my 'collection', operating them for some period ranging from 2 weeks ('didn't work so well'-e.g. needs more restoration) to 6 months (my Ranger II is way past that-but I can't bring myself to 'rotate'!)

Well, anyway, I had a nice chat with the guy, and he told me the history of the receiver. THIS radio was the primary receiver for the Executive Offices of Radio Free Europe in Washington, DC (or nearby.)

It had been re-tubed and air-freighted to RACAL England (RACAL - USA no longer worked on tube gear) for a complete tuneup. A similar return method was employed. Shortly thereafter, RFE shut down, and he was able to obtain the unit. During our conversation, he came to appreciate my fondness for receivers, and that I would suitably treasure the unit.

Bottom line is that, despite higher offers, he sold it to me to care for. It's beautiful. With its 1st-ever tube implementation of the Barlowe-Wadley Loop (the 1st production version of the Phase-Locked Loop), it is stable as a rock. Recently, I was able to obtain the matching LF Converter, extending the receiving frequency range from 12.5kHz (!!!) to 30MHz.

I felt Keith did such a good job on this description, it would be better just to quote it-with attribution, of course.

The RA37A / RA137A are Longwave converters for the RA17 series of receivers.
They cover the frequency range of 10-980 kHz. If you have ever wondered why there is a red scale below the black main tuning on the RA17 film scale now you know, it is for tuning when using an LF adaptor! It is not a logging scale as I have heard some people comment.

Both units were produced in two versions, one for the Europeans the other for America. The only difference between the two units is that the RA137 has a tuning scale for the pre-selector.

The controls from left to right are as follows: Attenuator 0-40db, Aerial range (pre-selector), Preselector tuning, Power ON-OFF, HF-LF selection for the main receiver.
Adding one of these converters to an RA17 can make a useful addition to an excellent receiver.

Connection is made to the RA17 by means of the RF and 1 MHz osc outputs on the rear of the receiver. The HT line has to be broken on the terminal block at the back of the receiver and connected to the converter to enable switching between HF & LF.
There is also an RA237 model which was made specifically for the RA117. It has an extra filter fitted as the RA117 does not have a tunable 2-3mhz filter.

This is a RACAL RA6790/GM. It is the BEST receiver I own. It is one of 3 or 4 receivers that I simply would never part with. Many of them have become available in the past couple of years because of the all the HF Marine Radio Communications stations closing. It is sensitive, has a ton of filter slots, and has the slowest

(selectable) tuning rate I have ever tuned. Turning the knob as fast as you can and still maintain contact with the fingerhole on the knob, its tuning is so slow, it sounds like an old Heathkit VF-1 warming up from cold!! Built-in BITE testing, 10Hz accuracy, very high stability, plus the LF/MF EPROMS (which I have), all combine to make it a truly awesome receiver.

National