[R-390] R390 progress

[Bob Camp]

Hi

Sounds very good so far!

I would definitely check the crystals for the dead bands. They may 
simply have come loose in their sockets.

The easiest fix of all is the 10KHz offset on the readout. Just center 
up the zero adjust, slip the counter and you're done.

	Take Care

		Bob Camp
		KB8TQ


On Apr 25, 2005, at 2:54 AM, Dan Merz wrote:

> Hi,  I listened to the R390 tonight for the first time after repairing 
> -
> more to go.
> So far:
> Put 12BW4's in place of 26z5's that were missing and rewired the 
> sockets
> Added two 75 ohm-10 watt resistors below the rectifier sockets in 
> place of
> missing 47 ohm resistors - a trial to start with,  seems ok
> Jumpered pins 4/5 to 2/7 and used 12BH7 in place of missing 3tf7
> Straightened a badly bent twinax female antenna socket
> Wired a replacement power connector obtained from Fair
> Added a missing knob, also from Fair
> Cleaned gear train in place with mystery oil
>
>
> The radio worked once I realized the previous owner had used enameled 
> magnet
> wire on some added wiring on the rectifier sockets - my connection to 
> it
> looked good but only connected after I did some scraping to get rid of 
> that
> enamel !!
>
> It appears to be reasonably aligned and  reads about 10 khz high on 
> both
> ends of the 1000 khz range.  So far only one dead band found up to 20 
> Mhz
> which was as high as I checked.   7 to 8 Mhz is dead.  I haven't 
> cleaned any
> switches so hopefully that's the problem but only one other band 
> showed any
> sign of intermittent connection.  The line meter appears dead.  The 
> carrier
> level meter appears ok.
>
> I still need a male twinax connector for the antenna socket - one 
> listener
> indicated he had one but I'm having trouble getting more info from him 
> to
> pay him so he can send it.  One other response offered an IBM server 
> cable
> with two connectors that were said to fit,  so that's my backup source 
> at
> this time.  My local electronics junk collector couldn't help me on 
> this
> one.
>
> Roy Morgan indicated he would provide a drawing/description of the fan 
> he
> installed on his R390 to cool the 6082 tubes.
>
> I was relieved that the radio worked and pleased that it's working so 
> well
> at this point.  The seller said it played weakly - at this point it is
> better than that in my opinion and I haven't messed with the tuned 
> circuits
> at all or changed any of the tubes.  I suspect that the haywired 
> resistors
> that were stuck in the 3tf7 socket were part of the problem before.  I
> removed the i.f. chassis to jumper the ballast tube pins and was 
> pleased at
> how nice it looked underneath there.
>
> Now I have to study the manual a bit to see how the alignment goes on 
> the
> 390 vs. the 390a - more similar than different I suspect,  Dan.
>
>
>
>
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