From: Garey Barrell 
Subject: Re: [drakelist] Drake R4B


Garey Barrell  made an utterence to the drakelist gang
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Steve -

Drake never provided a service manual for the 4 Series, other than the 
SPR-4.   The biggest problem is locating parts on the chassis.  I have 
made a parts locator manual for the C Line, maybe do the B Line one 
day!  It's a lot of work, and is not a big seller.  A sample is at

http://hr99.home.mindspring.com/R-4C_Servicez>

It makes it a LOT easier.   All the information you need to service the 
receiver is in the Drake manual, except where parts are located.

As for your R-4B, we'd need a lot more information to troubleshoot.  Is 
it low on all bands?  How low?  What is the signal strength of the 
calibrator?   Are all the tubes lit?  Especially V1.

Obviously the first thing is to see if the S-Meter is at 0 with no 
signal applied, and goes to 60 dB over S-9 when the RF Gain is turned 
full CCW.

If this is good, then check the bias voltage at TP-2 as described in the 
manual.   This must be very close to -1.35V and sets the sensitivity of 
the receiver.

Next is to try the Antenna, RF and Injection alignment as described in 
the manual.  Do a single band, using the calibrator, to see if any 
improvement can be made.  Do not bother with any of the other alignment, 
as it it almost certainly OK, unless of course someone has been 
"tightening all the loose screws".!

Let us know what you find!

73, Garey - K4OAH
Atlanta


Steve Schaub wrote:

> I'm restoring a Drake R4B that has low rx sensitivity. I have the 
> original manual shipped with the receiver, but was wanting to know if 
> there ever was a "service" manual available for the Drake
R4B? If this 
> manual ever existed, anyone know where a person can get a copy?
> Many thanks for taking the time to read...............
> ************************************************
> * ARS: W4PF
> * Steve Schaub
> * E-mail: W4PF{at}arrl.net 
> ************************************************
> /\/\/\/\/\/\/\/\/\/\/\ END OF TRANSMISSION /\/\/\/\/\/\/\/\/\/\/\/\/\/\/

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