[Amps] Comparison of PCB-mount RF relays

[Robrk]

I have a Motorola manual, from the 70's, what is an 8877, 2 to 18 mhz HF amp, using relays for the Pi switching. Part list says "special modified relay". The fuzzy photo looks like just 10 amp contact, open frame P&Bs. Think the mod is just a strap across the DPDT wiper. Getting ready to think about planning to try it with a pair of 813's or 572's.

Someone with a bigger brain do the volts and amps math.

Bob, K2RK 


Sent from my iPad

On Aug 7, 2010, at 7:35, Lee Buller <k0wa at swbell.net> wrote:

> 
> Jim, thanks for your excellent work and commentary.  
> 
> Now, the question I have....
> 
> Do you think these relays could be used in switching a PI-Net circuit in an 
> amplifier instead of the standard rotary switch?
> 
> Finding a suitable band switch for a legal limit amp is rather daunting and 
> expensive.  RF current in the PI_Net could be extremely high if I remember 
> correctly...on the order of 25 amps or so...but I could be wrong.  The relays 
> could be used to switch coil segments in or out and adding capacitance to the 
> tune and load controls.  What strikes me as interesting is that you could set up 
> a BCD diode matrix to control band switching with relays.  That could be coupled 
> to a transceiver for automatic band changing.
> 
> Comments?
> 
> Lee Buller - K0WA
> "A liberal arts major and a wannabe engineer"
> --------------------------------------------------
> 
> 
> 

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