Curt -
Here is a comparison that I wrote up a while ago.
>>>>>>>
The 2-B is an outstanding CW receiver, the dial calibration is a little
coarse by today's standards, but for just getting on the air and
enjoying a CW QSO it works as well as any. It has three (L-C) filter
bandwidths, (500, 2100 and 3600 Hz,) built in along with passband
tuning. The 100 kHz crystal calibrator was optional. The companion
2-BQ Q Multiplier adds a very sharp peaking filter and a nice tunable
null, both at the IF.
There is no matching transmitter for the 2-B.
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".
The 2-B isn't very far behind, except it will NOT transceive with
anything, and the dial calibration is not precisely linear.
<<<<<<<<<<<<<<<<<
Tom is correct on the 2-C, it is similar circuit topology to the 2-B,
but with tubes in the RF and IF stages only. Oscillators, Detectors,
AVC and AF stages are all solid state. Passband tuning is also
"non-tunable", just two fixed 2nd converter LO offsets for USB and LSB.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
<www.k4oah.com>
Hulett, Russell wrote:
My recent acquisition of a 2B and 4A, ownership of an R-4 together with some
discussions about the 2C got me interested in the relative capabilities of the
different Drake receivers. The discussion indicated the 2C was a low cost
entry-level receiver as compared to the 2B. Browsing the Drake virtual museum
only indicated similar sensitivities and selectivities.
Has anyone ever run definitive comparisons between the different Drake
receivers?
73, Curt
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