[R-390] What about this one

[Richard W. Solomon]

It uses a 28 vdc Dynamotor. Only needs a few amps to run it, 
but the turn-on surge for the Dyno is high. 
I use a 12 Amp switching supply and it sounds like an engine 
cranking until it gets up enough speed to run.
There are two Mechanical Filters in it.

This radio is rock stable. I can tune in an SSB signal, go in for 
another cup of coffee and when I return the SSB signal is still Q5 
copy.

The only thing I don't like is the Dial Zero Mechanism. It works 
but not as well as the R-390.
Also, due to it's rarity, finding a TM or it's equivalent is difficult. 
The BAMA copy is it's usual poor quality and it's missing some pages. 
Most of the Manual Merchants sell copies of the BAMA file.
WA5CAB has a nice copy that I may get if I decide to keep my radio.

73, Dick, W1KSZ

73, Dick, W1KSZ


-----Original Message-----
>From: k2cby <k2cby at optonline.net>
>Sent: May 24, 2010 11:53 AM
>To: R-390 Mailman <R-390 at Mailman.qth.net>
>Subject: [R-390] What about this one
>
> 
>I couldn't find much information on the R-648/ARR-41 but I did find a tube
>line-up.
> 
>They seem to be all the familiar R-390A high voltage tubes rather than the
>28-volt 
>tubes used in the R-392.
> 
>Also, from what I could tell the only voltage required by the R-648 is 24-28
>V dc.
> 
>There seems to be a whacking great power transformer on the right hand side
>of the 
>chassis. Does it have an internal dc power supply? Vibrator? Solid-state? Or
>am I 
>missing a 400 Hz power source connection?
>
> 
>
> 
>
>Miles B. Anderson, K2CBY
>16 Round Pond Lane
>Sag Harbor, NY 11963
>Tel.: (631) 725-4400
>
>Fax.: (631) 725-2223
>e-mail: k2cby at optonline.net <mailto:k2cby at optonline.net>  
>
>
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