[R-390] What is the difference between 390 and 390A

[Bob Camp]

Hi

The mechanical filters in the R390A are not bad at all. The ringing is 
not a major issue. The main point is that if you have a good enough 
situation the R390 not an A will sound a little bit better.

If you are fighting for the last couple of db with a strong signal just 
up band the 4 KC mechanical filter on the R390A will do a very nice job 
in AM mode. With an outboard gizmo like the Sherwood box you can do 
some odd stuff with the 2 KC filter as well.

	Enjoy!

		Bob Camp
		KB8TQ


On Apr 11, 2005, at 10:18 PM, ROBERT YOUNG wrote:

> I have heard that the 390A was better than the 390 for BCB DX'ing 
> because of
> the mechanical filters. I mostly DX for foreign DX on the BCB 
> frequencies
> and most are very weak against very strong domestic stations sometimes 
> 1 khz
> away. Will the mech. filters perform better for this purpose? I can 
> put up
> with lousy ringing audio if I have to to to hear a station that would
> otherwise be obliterated by QRM from a 50KW local 2 kHz away. Actually 
> my
> motto is you can never have enough radios anyway,
>
> Bob
>
>
> ----- Original Message -----
> From: <Flowertime01 at wmconnect.com>
> To: <r-390 at mailman.qth.net>
> Sent: Monday, April 11, 2005 9:41 PM
> Subject: Re: [R-390] What is the difference between 390 and 390A
>
>
>> Bob,
>>
>>> From 68 through 75 I was an Army Tech (33C) and made a living 
>>> servicing
>>> R390
>> and R390/A for literally thousands of Ops (05H) who made their living
>> lessening to them.
>>
>>> From the listen point of view, there were no signals either receiver
>>> could
>> not hear. Would an Op copy the signal was a different subject?
>>
>> The R390 IF does not ring like the mechanical filters in an R390/A a 
>> ditty
>> OP
>> did not care about the IF deck ring. Us SSB and AM listeners do 
>> notice the
>> difference.
>>
>> The R390 and R390/A are both bad mouthed for the AM audio quality. 
>> There
>> are
>> easy work around.
>>
>> The R390 uses a pair of 6082 series voltage regulators that you can 
>> cook
>> on
>> (at least heat rations). With today power line voltages in the states 
>> the
>> power
>> supply regulation is over kill.
>>
>> Sensitive wise the receivers are pretty equal and better than any 
>> thing
>> else.
>> The Army tried a lot of other receivers and the R390 R390/A were the
>> intelligence intercept receivers of choice. When you need to roll up 
>> and
>> down the
>> bands chasing RTTY, and Dits on a demanding schedule The R390 and 
>> R390/A
>> would get
>> it on frequency and out of the atmospherics day in and day out.
>>
>> Now if you just want to listen to a little AM radio on Saturday 
>> afternoon,
>> there are some other options.
>>
>> Either model any manufacture. There all above average. Once you get it
>> working again you will keep it working and wonder why you were ever
>> without one.
>>
>> Roger. KC6TRU
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