Topband: Antenna relays

[MU 4CX250B]

For my StationPro controller I tested a variety of relays and
eventually settled on the Tyco/Shrack (Mouser 655-RTB14012F). There
are about 3000 of these relays in use now by StationPro builders, with
no failures reported except for one defective relay with an open coil.
All the SP builders run QRO, including several with Alpha 77S amps. In
my own station, I use them with two large homebrew amps, an Alpha9500,
and a Johnson Viking KW AM rig.

Some considerations are the length of the internal straps to the
contacts (should be short), the diameter and thickness of the contacts
(should be large) and the orientation of the coil, relative to the
straps (orthogonal, to minimize inductive coupling).
Whatever relays are used should be operated so they are never hot-switched

I did life tests on the relays, switching them under full load (using
a space heater for the load) at about 20HZ until they failed, and
found wide variation among different brands having nominally similar
ratings. On the life tests, the relays were hot switched, and failures
were normally because the plastic bodies softened with heat and
deformed the contact alignment.

73,
Jim w8zr


Sent from my iPhone

> On May 18, 2015, at 6:48 AM, Mike Waters <mikewate at gmail.com> wrote:
>
> Are you hot-switching these?
> Or, could they be placed at a point where the current is higher than the
> relay's rating?
>
> In any case, I bought three or four different replays based on a discussion
> here (around October 9, 2014), and FWIW, I see just now that none of them
> are Omron G6RN. They are:
>
> Mouser 653-G2R-1-E-T130DC12 (10 kV, not sealed); internal photos at
> www.w0btu.com/files/misc/Omron_relay_G2R-1-E-T130/
> Mouser 655-RTE-24012
> ? K1CK012W (16 A)
>
> This is just food for thought. I have yet to finish the remote antenna
> switch project here using those.
>
> 73, Mike
> www.w0btu.com
>
>> On Sun, May 17, 2015 at 9:55 PM, Tim Shoppa <tshoppa at gmail.com> wrote:
>>
>> I think I posted some details here about how I was using Omron G6RN
>> antenna relays ...  they held up OK for me in heavy contest usage - until I
>> got a legal limit amp.
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband