[Amps] Building an Amp 101

[Al Kozakiewicz]

To make it clear, I've never tried this so I'm not speaking from personal experience.

But it seems logical to me that if a vacuum relay is required for the voltages and duty involved, then a bandswitch is out of the question as well, isn't it?  My thought is that, putting aside questions around stray-L that might arise from the insertion of a relay, it's easier to find a relay with sufficient contact spacing than it is to find a bandswitch with a large enough diameter to maintain the same spacing between contact elements.

I guess these sorts of problems is why it's called engineering and not science!

Al
AB2ZY

-----Original Message-----
From: MU 4CX250B [mailto:4cx250b at miamioh.edu] 
Sent: Sunday, January 19, 2014 9:32 AM
To: Al Kozakiewicz
Cc: amps at contesting.com
Subject: Re: [Amps] Building an Amp 101

Relays are certainly a possibility, Al, but for a nine band amplifier things get a bit complicated. My latest project ( 90% completed) is a duo - band 80m/160m amplifier with a pi- L tank circuit, and for that I am using two DPDT vacuum relays, each of which cost over $100.
Scaling that up to a nine band amplifier doesn't seem very practical or cost-effective.
73,
Jim w8zr
Sent from my iPhone

> On Jan 18, 2014, at 8:52 AM, Al Kozakiewicz <akozak at hourglass.com> wrote:
>
> Why not use relays appropriate for the switching duty?  Then the bandswitch can be just about anything or even remotely controlled.  Plus you can locate the switch where it's convenient to operate instead of being constrained by the necessity to place it close to the RF components.
>
> Al
> AB2ZY