[Milsurplus] R390

[bill riches]

Easy - if no antenna trimmer it is an R-390!

73,

Bill, WA2DVu

On Sun, Aug 23, 2020 at 12:21 PM Gordon Smith <gfsmith at cox.net> wrote:

> HI Mike,
> Here is a basic discussion on the differences between the "A" and
> "Non A":  "The R-390A was a cost reduced R-390. To do this, they
> reduced tube count from 32 down to 26. One stage of RF and 4 stages
> of IF, rather than 2 stages of RF and 6 stages of IF. Also, the "A"
> has a simpler, more conventional power supply without the regulator
> tubes.<P>The biggest difference is that the "A" has, with very, very
> few exceptions, mechanical filters."
>
> Discussion can be found here:
> https://www.antiqueradios.com/forums/viewtopic.php?t=5427
>
> So you should be able to find out quickly what version yours is
>
> 73, Gordon KJ6IKT
>
>
> At 08:55 AM 8/23/2020, mike christie via Milsurplus wrote:
> >Content-Type: multipart/alternative;
> >         boundary="----=_NextPart_000_0002_01D67944.41CBA350"
> >Content-Language: en-us
> >
> >I've  inherited  an R390 it doesn't have a data plate on it so I
> >can't tell if it's A or not.  I have it up and running but the
> >sensitivity is really bad on all bands.  I can hear WWV on 10 and 15
> >Mhz but not really strong and I went to the Amateur bands and I
> >could hardly hear anything there either.  All the controls are
> >working such as the BFO, limiter, Broad & Sharp,  RF gain etc.  All
> >the tubes are lit and I am getting background  noise. I've switched
> >between antenna inputs and I get the same results.  When I'm tuned
> >to WWV the Dial is correct for at least on  10 & 15 MHZ. Also I can
> >hear when the antenna is plug in also.  So since I'm getting back
> >ground noise on all bands,  I'm thinking I've got some bad tubes at
> >least on the front end.    I've used one when I was I in USMC so I
> >know what their capable of.
> >Can some give me some pointers as to what maybe the problem?
> >Thanks
> >Mike
> >W1ZFB
>
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