Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang
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Howard -
Here's an extract from an earlier post I made about the R-4 series
receivers.
The R-4 is almost a 2-B, just with a linear PTO and 1 kHz dial
calibration. All tubes. Very similar in operation, and will
transceive with the matching T-4X for an excellent CW station. Four
filter bandwidths, (400, 1200, 2400 and 4800 Hz,) passband tuning, noise
blanker, LC notch and 100 kHz crystal calibrator built in.
The R-4A (early 13 tube model) is an improved R-4, almost identical
specifications. PTO and Band Oscillators converted to solid state.
The R-4A (late 11 tube model) almost identical specifications. Product
detector, BFO, AGC and low level audio stages converted to solid state.
The R-4B (early) is very similar to the late R-4A, minor modifications
and crystal calibrator multivibrator for 25 kHz markers.
The R-4B (late) almost identical except PTO changed from bipolar to FET.
The R-4C (early) very similar, except IF filters changed to crystal
filters. Only the 2.3 kHz filter is standard, 250, 500, 1800, 4000 and
6000 Hz BW are available as options. The 4000 & 6000 Hz filters are
normally installed in a special socket under the chassis and are
effective on AM only. Four position filter switch. The noise blanker
was optional. Entire audio chain solid state, tubes used only from RF
to IF, all other stages and oscillators solid state.
The R-4C (late) same. Five position filter switch.
The 2-B through the R-4B used L-C filters in the IF. This type of
filter has much gentler slopes, which means that nearby signals are
still heard, just at reduced levels. The crystal filters are steep
sided, more like the crystal filters in today's receivers.
Personally, I prefer the L-C filters for all except heavy duty contest
use. I like to hear what is going on around my frequency, instead of
"listening with blinders on"...
The T-4 series transmitters are all pretty much the same, the T-4X had 4
pole crystal filters while the T-4XB and C had 8 pole filters. The
later ones therefore had slightly better carrier and unwanted sideband
suppression, neither of which has ANY effect on CW operation.
ANY 4 series receiver will transceive with ANY 4 series transmitter, mix
and match. There are minor things like the B line had a neon indicator
light under the dial to show which PTO was controlling in transceive
while the C line just turned the dial lamps on or off. The R-4 and R-4A
had neither, so you had to look at the switch!
My opinion..... The R-4B is probably the best receiver overall. It has
great audio, smooth AGC, all the filters and noise blanker are built
in. The L-C filters are not quite as "drop off the table" selective,
but I prefer that for casual QSOs.
The R-4C has poorer audio, a little harsher, the "better" (?) crystal
filters are extra, and the noise blanker is extra.
The R-4 and R-4A are just earlier iterations of the R-4B, and are not
quite as refined, although some say they prefer the early R-4A to the
R-4B because the tube type product detector in the R-4A is "cleaner".
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B & C-Line Service Supplement CDs
<www.k4oah.com>
Howard Traxler wrote:
"Howard Traxler" <[EMAIL PROTECTED]> made an utterance to the drakelist gang
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Hi again all. Here's a question that will require, probably a subjective
answer:
For about 30 years, I used an R-4A and loved it. I now aquired an
R-4C--without any of those plug-in filters. I don't like it much at all.
So I got another R-4A and was hoping to tweak it up to be like the one I
used to have.
Question: Why did I not need those filters in the R-4A and will I like the
R-4C more if I get the filters for it? Which receiver should I put my
effort into? I like to work both SSB and CW.
Thoughts anyone? Thank you much.
73, DE Howard, WA9RYF
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