[R-390] Slaving R-390s again

Wed, 17 Sep 2003 20:09:10 -0500

Hi Jack and Group

I may be wrong but I think your phase shift experiment would be shipwrecked
because of the mechanical filters...my understanding is that the military
experienced the problems with the phase shift problems related to the
mechanical filters in the R-390A when used in DF setups and ordered a
variant that put an R-390\URR type filter scheme in the R-390A to get around
this. (L-C filters)

There are others that know much more about this than I on this list...and
will probably add to my comments.

Cecil...

----- Original Message ----- 
From: "Jack Antonio" <[email protected]>
To: <[email protected]>
Sent: Wednesday, September 17, 2003 7:16 PM
Subject: [R-390] Slaving R-390s again

> Hi all
>
> To answer one of the replies, my goal here is not diversity reception, but
> the
> phase relationship between the 455 kc outputs from the two receivers.
Thus
> the using of common oscillators between the two receivers.
>
> Another question, not really R-390 related, but it's the reason behind the
> original question.
>
> Lets say we are receiving a signal on 4550 kc. The frequency is not really
> important, I
> just chose it because it is 10 times 455 kc.  If the input signal
undergoes
> a 90 degree
> phase shift, what phase shift does the 455 kc if undergo?
>
> Would the 455kc phase shift be related to the time difference of 90
degrees
> at
> 4.55 mc? In which case I would expect to see a 9 degree shift at 455 kc.
Or
> does the
> heterodyne process mask any phase shift?
>
> So there is the basis of the experiment, using two R-390A's, both driven
> from the
> same oscillators, and using one receiver as the reference, then varying
the
> phase
> of the input signal into the other, and seeing what happens at the IF
output
> jacks.
>
> Jack
>
> Jack Antonio WA7DIA
> [email protected]
>
>
>
>
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