George -
Interesting problem. I had one of the very first R-4's in 1965, but moved to an R-4A as soon as they came out. I just recently picked up another R-4.
Anyway, this alignment procedure is specific to the R-4. All the other R-4 series receivers make a mechanical measurement of the four slugs in T1-T4 for each band setting of the Preselector control.
The manual for the R-4 says to use the 13.6 MHz crystal with the dial set to 1.000. This would set the receiver to 3.0 MHz, and with the Preselector at "0" has you adjust the four 3.5 MHz trimmers for peak at 3.0 MHz. You then switch in the NORM 14.6 MHz crystal and adjust T1-T4 to peak at 4.0 MHz. Repeated iterations of adjusting the capacitors at 3.0 MHz and the slugs at 4.0 MHz should eventually result in the combination "tracking" over that 1 MHz range.
I can only assume that this procedure is to set the mechanical locations of T1-T4, since the measurement procedure specified in other R-4 manuals is NOT used in the R-4. In fact, all the later manuals warn against moving the individual slugs and insist that they all be exactly the same "height" at a given Preselector setting.
I don't know if you could just line up all the slugs mechanically, since obviously Drake didn't control the height of the windings in T1-T4 in the R-4. They probably found that they "could" control the winding height precisely enough to eliminate this (relatively) complex alignment procedure in favor of simple measurements, and used that method from then on.
To be assured of maximum sensitivity in the R-4, I guess you'd have to invest in a 13.6 MHz crystal. It doesn't have to be anything special, since the dial is tuned to the correct frequency. You could use a 13.5 MHz crystal and adjust the dial to 0.900, etc. so you might find a junkbox crystal (i.e., 13.543 MHz) that would allow you to tune the receiver to 3.0 MHz at "some" point on the dial for the "T" adjustments.
Or you could just leave the slugs where they are and hope no one has messed with them since they left the factory! :-) Just start with step 8 in Section E.
There is a way, although I've forgotten how, to receive WWV on the R-4 series receivers by using the "other" mixing product on one band. Seems like you set the bandswitch to 20M and set the Preselector in the 40M area to get 10 MHz WWV. It's described in a Hints and Kinks in March 1971 QST, but I can't get to my 1971 QST's at the moment!
73, Garey - K4OAH Atlanta
George KB2Z wrote:
Hi Mark,
In my original post that's the reason I asked if there was a work around for the alignment.
The rx has a 12.6 xtal installed.
Per the manual, (p.32 alignment instructions) 13.6 mc x-tal required. The manual I have is from BAMA, but I checked it against the one at WB4HFN. http://www.wb4hfn.com/DrakeManuals/R4/Manual_R4.htm
Page 34, steps 1, 2, 3 says to use that xtal with Band at 3.5 and preselector at 0,,, adjust the 4,,, 3.5M caps. for max s-units
Maybe using a harmonic for sensitivity?
Step 4, Set xtal to NORM, preselector to 3.9 adjust T-1 through T-4 for max s-units.
Steps 1, 2, 3, seem to be a preparation for tuning T1/T4 in step 4.
Step 12 has you retune the 4 caps for the 3.5 band in NORM pos.
When it gets to the bottom of the page (35) for peaking the 4, 1.5/3.0 caps, step 13, It instructs you to use that 13.6 xtal with the preselector at 6.
Page 35 has you use the 13.6 xtal to tune 2.5 WWV to adjust the 100kc osc.. That's the only part of that xtal that is straight forward.
I want to do this right, but it seems that skipping the first 4 steps (T-1/T-4) would be the sensible thing for me to do. The rx works good, but I know it could work better.
As always thanks all for the advise and guidance, George KB2Z
At 09:41 PM 2/7/04 -0600, you wrote:
Hi George,
Think you mean a 12.6 MHz for 160m? I just ignored the 160m alignment procedures on my R4A and had no trouble without it.
I'm pretty certain all the R4/T4/TR3/TR4 series use series resonant 3ed overtone HC6/U crystals. The +/- 50 ppm standard tolerance seems to work fine for me. I've had to replace a few in TR3/TR4 that were WAY off frequency. I'd be wary of buying any old crystals even though I haven't seen this in R4/T4's. I've had good luck with Petersen Radio for new "rocks" and received stuff the same week I ordered them. I just email him exactly what I want and typically get the crystals way before I get the bill. So far they have been dead on freq., fast and I like doing business in that manner.
73, - Mark K9MRK ----------------------------------------
Petersen Radio co., Inc.: [EMAIL PROTECTED]
Drake 4 series spec.:
HC6/U holder
3ed overtone
Series resonant
+/- 50 ppm tolerance (std.)
---------------------------------
Thank you for the inquiry. The crystals are $11.00 each plus $3.50 postage for up to 5 crystals. Delivery is usually 2 - 3 weeks
and payment may be made by check or money order upon your receipt of the invoice. If you want to order, I need to know the type of
holder that you need and your mailing address.
> Good evening all, > > Would anyone have a spare, "13.6 mc parallel resonant third overtone > crystal designed to operate into circuit capacity of 32 pf"? > I need one to align an R-4 per the manual. > Is there a work around to peak it without the crystal? > I can order a new one if needed. > > Thanks in advance, George KB2Z
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