From: Garey Barrell 
Subject: Re: [drakelist] Needed: 13.6mc R-4 x-tal


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:

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