Joe,
I have had good results with low cost (10 Euro) relays designed for
switching single phase mains electric power (230 Volt, 20 Amp rating) with
a 3CX3000A7 up as far as 20 metres. The relays tend to be a little slow
(30 - 50 ms?) to changeover, so I would not recommend them for QSK-type
operation without some sequencing. In fact, I use two identical ones on my
amp., one for input and one for output, with just a little 'j' correction
on the link (capacitor of about 30 pF from the link point to ground)
between the two relays in order to flatten out the VSWR for the exciter
when used with the amp. in bypass. The input relay is a 24 V coil part;
the output a 12 V coil part with a series resistor. This was deliberate
attempt on my part to make the output relay a little faster to changeover
than the input when using a 24 Volt control supply.
I believe this configuration would be good up to 10 metres.
Regards.
Mark.
-----------------------------------------
At 14:26 06/05/2005, you wrote:
>Hello to all
>
> I like to ask from were I can buy a good relays for
> RF as I am going to use them to switch the loading fixed capacitors as I
> used in my amp vacuum variable on the plate and variable inductor and I
> am going to use fixed loading capacitors so I need to switch them....the
> tube I am using is the big one 3CX3000A7...
>Many thanks
>joe
>9H1GT Joe Francalanza
*******************************************
Mark Hill - G4FPH
E-mail: g4fph@mjha.co.uk
Current web pages at: www.qsl.net/g4fph
Old web pages at: www.g4fph.freeserve.co.uk
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