[UK-CONTEST] Deaf 756 pro III

[Clive Whelan]

Hi again Marios

I'm not sure what you mean by

<<

I plugged the antenna directly still same
problem.

 >>

There are only two SO239 sockets on the back panel, one for ANT1 and 
t'other for ANT2, so how else could you connect the antenna other than 
directly?

When pressing the ANT1/2 switch at the top left of the display screen 
there should be a faint click as this is relay controlled. If not, this 
might be a clue.


When I switch from ANT1 to ANT2 (even on say a dead 14Mhz band this 
evening)  the white noise drops perhaps 10dB and the rx indeed sounds 
stone deaf, because there is no antenna connected to that SO239 socket.  
This may seem soooooh obvious, but I've found that  in such situations 
that I make really stupid mistakes and ignore the glaringly obvious  ( 
I've been nominated for a UNICEF award for ignoring the obvious ;-) ). 
This is sooooh obvious, but how do you know that the antenna you have 
plugged is indeed viable; iow could it be dissed at the connector or 
wherever. When you plug the identical antenna in to another rx, are 
things normal? Even 10ft of wire plugged in should generate some white 
noise on an LF band; does it? Is your rx deaf or is your antenna gone to 
the tuning range in the sky.

I run a pair of PRO3s here, and-shock, horror- I have transmitted on the 
same band a couple of times, without ill effect; iow the rig is not that 
fragile.

Sorry if any of this sounds condescending but it's worth the risk.


73



Clive
GW3NJW
Marios Nicolaou wrote:
> Hi Clive
>
> thanks for the reply!
>
> The radio was working OK beforehand and the display was very
> active.The display/scope is now flat. I  tried ANT1/2 selection and
> there were no signals. I plugged the antenna directly still same
> problem. I havent tried using a receiving antenna to see if this makes
> a difference (antenna relay should be bypassed this way). I will do so
> this weekend!
>
> Thanks for your input
>
> 73s
>
> Marios
> G0WWW
> 5B4WN
>
>
>
>
>
>
>
>
>
>
> Well not on either of mine there isn\'t!
>
> Frying sounds unlikely. More likely in my experience is selecting the
> wrong antenna- topmost button to the left of the screen. This is easily
> done in the heat of the battle and doesn\'t leap off the display at you.
> Can be checked visually in no time. I hope I\'m right.
>
> More seriously keying of a legacy amplifier such as the SB220, without
> an intermediate relay or solid state switch,  will fry the PRO3 antenna
> c/o relay. This is verrry poor design I have to say.
>
>
> 73
>
>
> Clive
> GW3NJW
>
>
> --
> Marios
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>