Topband: TX relays

[Mike Waters]

Thanks for the advice. I've already calculated the voltage at the feedpoint
of my 160m inverted-L on 80m at 1500w (using EZNEC), and it's only a little
over 3 kV.

I just popped the cover off a little Omron PCB-mounting relay that I forgot
I had, rated at 10 kV. The spacing between the SPDT contacts and the coil
actually looks greater than that open-frame relay. I was thinking of
seriesing the contacts on two of these relays, if necessary.

I should take a photo and get the Omron P/N later for this thread.

73, Mike
www.w0btu.com

On Thu, Oct 9, 2014 at 7:57 AM, Tim Shoppa <tshoppa at gmail.com> wrote:

> Mike, I would be concerned about using these small relays for non-resonant
> antenna switching where the impedance at the switch point may be wildly
> away from 50 ohms.
>
> This is the relay I use to switch tuning networks at non-50-ohm points:
>
> http://www.deltrol-controls.com/products/relays/power-relays/900
>
> Deltrol is the brand you get if you order from McMaster-Carr but all the
> big relay manufacturers sell these open frame relays.
>
> I also bend the relay contacts for wider spacing as recommended by N6RK in
> QST (page 66, May 2009 QST Hints and Kinks, "Increasing Relay Voltage
> Handling"). Open contact gap of 0.5 inches is readily achievable.
>