Him Paul:
There is a small dark metal spring pc that goes inside the brass
coupler. It is approx 1/2 or 5/8" long x 1/8 wide made from spring
steel. It has a slight arc bent into it. It rides on the two flats of
the shafts and is held in place by compressing against the inside of the
coupling. The first few times you assemble one, it is a trick needing
three hands, but after a couple, it gets easy...many of the T4Xx
transmitters used these on the tune and load shafts also. (some have a
plastic coupling.)
If you really need it, I can take a picture of the set-up for you. FIND
THE MISSING PART!!
Curt
KU8L
Paul Christensen wrote:
Now I've done it. After a complete cleaning of the R-4B front panel
and associated hardware I cannot get the crystal select switch shaft
to engage onto the switch shaft. A brass coupler is used to join the
two pieces but I failed to look closely at the relationship between
the coupling and the two shafts. Each shaft has a flattened end but I
see no what to synchronize them with the brass coupling -- it just
spins. It's as if there's another part that I cannot account for.
I also found a small curved washer which goes....where? The larger
curved washer is placed on the VFO shaft and I'm fine there.
Thanks in advance for any help to get me out of this rut. Grrrrr...
Paul, W9AC
----- Original Message ----- From: "Garey Barrell" <k4...@mindspring.com>
To: "drakelist" <Drakelist@zerobeat.net>
Sent: Friday, February 25, 2011 10:18 AM
Subject: Re: [Drakelist] Drake R-4B
Paul -
Ripple on Calibrator signal probably power supply ripple, D6, C190,
C192.
S-Meter drift is gassy tube (grid emission) probably V4 or V5,
possibly V1.
Phones jack 'used' to be on the front panel, but interfered with the
controls on either side. Note small circle where phones jack USED to
be. The hole IS in the subchassis as well, so if you want it there,
yours won't be the first to have it!
AGC SLOW cap is C109.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
Paul Christensen wrote:
Now that my Drake 1A restoration is complete, it's off to the races
with a recently-acquired R-4B. BTW, Hartzell re-painted the 1A
cabinet and it looks great. Also, Tom at HayseedHamfest.com
provided me with an exact replacement multi-section PS cap for the
1A, although it's not listed on his website. Ready for this? The
can is made from copper and looks great against the copper chassis.
Perfect retrofit without any hassles.
My first R-4B operating impressions below. Keep in mind this unit
requires some TLC.
- Plenty of sensitivity on all bands. Easily peaks noise with no
antenna connected;
- High IMD on audio. Listening to the Xtal calibrator, I hear IMD
that sounds like perhaps either 60 Hz or 120 Hz is mixing
somewhere. It may also be the result of B-H distortion from the
output transformer into high quality headphones with a 40-ohm load
Z. In any event, I need to investigate further. Overall audio
passband response is mediocre. I was expecting a wider audio
passband. At this early stage of ownership, the audio is nowhere
near the quality of my 1A nor R-4C with Sherwood AF mods;
- Audio output tube way too microphonic. I do not sense this much
mechanical sensitivity with the 1A receiver and the output stages
are similar;
- The S-Meter starts at S8 then drifts to down to S0 after about
five minutes warm up. Is this behavior normal for the R-4B? Either
a weak tube in the AGC loop, leaky cap, or out-of-tolerance resistor
changing value with heat may be the root cause. More investigating
needed...;
- Why the headphone jack on the side and not on the front panel? A
target point is marked on the panel for a 1/4-inch jack and the
chassis easily supports it. Very strange;
- AGC *way* too fast on both settings. Just my opinion, but AGC
Slow is more like where I would want the Fast setting. AGC Slow
needs R/C help to get its recovery slower. Easy enough to fix;
- Nice VFO feel, even better than early R-4Cs, and equal in tuning
feel to late R-4Cs with metal/Nylon gears. Excellent PTO stability.
I would appreciate any comments on the recovered audio and S meter
abnormalities before digging in. Many Tnx to everyone on this list!
Paul, W9AC
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