On Thu, 26 Jul 2007, Ken Arck wrote:
> Firstly, in the case of your additional bandpass cavity - if cavities
> are properly tuned to 50 ohms, the length of 50 ohm coax between them
> doesn't make one bit of difference. The problem most people have with
> proper cavity/duplexer tuning is that they don't maintain a 50 ohm
> load on ALL ports when they tune 'em. So when they're placed into
> service, the port impedances are different and the tuning of the
> cavity/duplexer changes. Which is why you should NEVER EVER tune
> either without at least a 3 dB 50 ohm pad on each of the ports. From
> your description, I'm willing to bet you didn't use pads :-)
Now, from a perspective of impedance matching, wouldn't it make sense to
use a circulator at the input of the reciever so that it is also matched
to 50-ohms?
>>>>>
rf -> circulator -> rx
|
-> dummy load
?
Since we know that some RXs aren't 50-ohms, nor are some TXs.
I'm looking at this strictly from the point of view of matched
impedances.
--
Kris Kirby, KE4AHR <[EMAIL PROTECTED]>
* WAR IS PEACE * FREEDOM IS SLAVERY *
* IGNORANCE IS STRENGTH * KETCHUP IS *
* A VEGETABLE *
