Hi Trevor
Any open frame relay like that can destroy your reception. I feel sorry to
see people selling and even recommending this type of relay, it is a shame.
The issue is speed and not current.
You can try this one for EU25 on ebay (4 mSec)
http://www.ebay.co.uk/itm/RF-vacuum-relay-Vakuumrelais-VR421-Siemens-270-Ohm
26-5-V-/281975931582
The destining relay is critical and can cause big problems if not
implemented right.
1- decouple and shield the relay line, sent 26V and switch to ground during
TX.
2- Never send voltage during RX, any relay has capacitance and can feed
noise into the TX antenna if not protected from common mode noise , Doug
NX4D spent U$ 200 ++ on a 12V vacuum relay and the relay was energized
during RX, the time to RX is very long and the relay gets hot and can and
will generate noise. Doug lost VK0 and E31 due a s2 noise originate on his
detuning relay.
3- Fast is always better the proved and reliable Jennings RJ1A-26S relay
that you can buy everywhere for U$50, is only 2 ms.
4- Sequencer is always recommended, and a delay on the RF generated is a
must.
5- Choke, and choke , burry the cable, common mode noise is a huge problems
for 160 and 80m,
I hope you can fix that,
73
JC
N4IS
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of MR TREVOR
DUNNE
Sent: Sunday, November 12, 2017 7:21 PM
To: topband List <topband@contesting.com>
Subject: Topband: Relay info needed,
Hi All
So after I got my vertical all tuned in I have been having a blast on TB
over the last week or two,
Thanks to everyone who helped me with that by the way, there was too many of
you to reply to everyone but I can't thank you all enough,
Anyway on to the next problem,
I built a small relay box to disconnect the vertical from the coax to reduce
re-radiated noise on my RX antenna,
This evening I was checking and TB seemed very quite and it seems that the
relay has burnt out, ( iwent out at 11pm to short it to work the 9U for a
new one)
it's a 12v 30amp automotive relay one you would use for spot lights or an
air horn ect,
I'm guessing this isn't up to the job, I have the relay in line between the
end of the vertical and the top of the coil as that where I was told to
place it,
Can anyone recommend a better relay for the job, ideally it would be 12v
coil as thats what I have going out to the box,
I was looking at some split charge relays rated at 200 amps would that be a
better job or failing that Array solutions have some relays that might work
but by the time I'd get them over here would be expensive,
https://www.arraysolutions.com/rf-10
Thanks
Trevor
EI2GLB
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