[Drake] R-4C Sherwood mods

[Jordan Arndt]

In 17 years of owning and using 5 different  Drake R-4C receivers, All of which
were the later models with the 5 position panel selectivity control, I found no
other single change that did more to increses the useability more than the
addition of the GUF-1 Front end filter...each of the R-4C's I've had either had
the filter, or I added it myself to the radio. It simply transformed all of them
into serious DX'ing receivers... No longer was I trying to stay away from QRM
and splatter, I actually found wide open spaces
where I could actually hear things that were covered by splatter and QRM in a
basically identical R-4C but , without the GUF-1 filter...

The difference is mostly noted in crowded bands with strong signals such as 80m
most evenings, or say 20m during a contest Saturday....I actually had to go look
for signals, instead of playing " follow the splatter ".....the splatter simply
wasn't there, although is a few cases, I could still hear some, but in every
case, it began less than 2 khz from "true" tuning of the desired signal.

Basically the same findings as founf at:
http://www.dproducts.be/Drake_Museum/the_guf.htm

73 de Jordan...


Thomas Beltran wrote:

> >   I need some advice on which mods are
> > "must haves" and which ones are "nice to haves".  I'm mostly a CW op,
> > but some SSB also.  What is your recommended "priority list" for the
> > Sherwoods?
>
> >
>  Darrell:
>
> You'll no doubt get a lot of opinions on this one.  By way of background, I
> have two R-4Cs left, one with all the mods, and one completely stock, in the
> mid 28K serial numbers.
>
> I think at the top of my list is the First IF CW filter and the newer
> replacement power supply board and, the capacitor kit.  I always hated the
> hum I got when using my radios with headphones - not a 30 year old radio,
> but back when they were new in the '60s and '70s.  After a few hours, that
> hum although very very low, was always there and it bugged me (I also get
> bugged by some flouresent [sp?] lights).  With the power supply and cap kit,
> I can turn my radio almost all the way down and copy signals without any hum
> whatsoever.  As far as the CW filter, I'd get a board with all the relays,
> so later, you can add the SSB filters if you so desire.
>
> > I assume the audio amp and product detectors are at the
> > top???
>
> I have them as well as all the other mods in my radio, but I think the mods
> I've listed above were the most dramatic for me (unless you plan on doing
> what I did, and ordering them all in one fail swoop).  I installed them
> separately over a period of a year, and tested each one before installing
> the next, and compared it with my stock radio.   I understand that the audio
> amp reduces the heat, but as far as a real tangible difference, I don't hear
> much difference when I compare my completely moded radio with stock one.
> I'm curious about other people's experience.
>
> The only thing I don't have is the ssb first IF filter kit, but I have the
> board with all the relays.  Right now, I have the GUF 1 and the stock Drake
> first IF filter.  That was a surprise, after hearing how the GUF-1 would
> completely change the radio, I couldn't tell the difference.  I also
> switched the filters - the GUF-1 is in the stock position, and the original
> filter is out next to the CW first IF filter.  I was concerned enough, that
> I sent my radio to Sherwood - he said (1) that I correctly installed
> everything, and (2) he didn't find much difference either.  Anyway, after a
> few months, I had noticed that I could tell the difference on AM.
>
> Rob also installed the detector for me and aligned the radio, so I know all
> the mods are installed properly.  I plan on taking out one of the roofing
> filters (stock or GUF-1), and installing the SSB first IF filters.  In any
> case, the radio is terrific, albeit a little pricey - I think the mods come
> to about $ 800.00 with the SSB filters.  Tom W6EIJ
>
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