Re: [TenTec] Lone voice in the wind

["pfizenmayer" <pfizenmayer@qwest.net>]

Carl and others - I have never encontered a condition with both rx on same 
freq, not to say it could not happen if both were general coverage . But I 
think it has to do with mathematical resolution limits in the two 
synthesizers . They are "phase locked" in that both start from the same TCXO 
but the schemes are different.  For instance you can set the sub on VFOB and 
use 1 hz steps but the error is something like 5.333 or 5.667 hz so you 
still cannot get both RX on same freq. You can go into the RS232 commands 
but those are also limited to 1 hz steps.
I have toyed with building an external LO for either the main or the the sub 
RX so they could at least be on the same freq but would not be truly phase 
locked - I suspect you could get them close enough for many uses.
There is another factor that is not too important in many applications but 
are in  some applications and that is that the delay through the main is 
substantially different than the delay through the sub rx. Put an external 
keyed signal into the input - both rx on same antenna input and look at 
recovered audio on a two channel scope .
Carl - can you get deep enough into the guts to do sub hz steps ????

I agree about what was said about true diversity - I begin to sense the 
improvement even using the sub on 1 hz steps and getting close. I really 
wish TT would quit saying the O is capable of "diversity" reception - but 
guess its how you define "diversity". Everything I have heard about the K3 
says they truly have it - and I assume the two delays are the same , dunno.
73 Hank K7HP


> > My N4PY Orion software has can be operated in diversity mode.  And my
> > program has an adjustment in it to allow for a slight frequency offset in
> > the 2 receivers and correct it.
> That sounds interesting. Can you explain how it works? I thought the
> reason the two receivers are always off frequency by some small amount
> is that they use different PLL schemes, with different minimum
> resolution step sizes. How can software change that? Perhaps I've got it
> all wrong.
>
> Even with different step sizes, at some frequencies the two receivers
> might be on exactly the same frequency. Maybe the N4PY software can be
> operated so that only these particular frequencies can be tuned?