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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W4AMV on February 17, 2023, 02:20:05 PM



Title: DOW KEY RELAY
Post by: W4AMV on February 17, 2023, 02:20:05 PM
What is the DC coil R for a 110 V dow key relay. The one I have will not pull in although the coil is excited. The coil R I get is
in line with a 2 W rating. Is there an obvious mechanical tweak on these when they fail to pull in?

Thanks,


Title: Re: DOW KEY RELAY
Post by: W4AMV on February 17, 2023, 10:40:15 PM
This is a DC relay. Do not assume when one states 120 V relay... AC.

Lesson learned.


Title: Re: DOW KEY RELAY
Post by: W4AMV on February 18, 2023, 12:06:24 PM
Here is the isolation. Better than I expected. On 40 meters above 60 dB. Be prepared to clean Tx contacts, this one was open. De oxit and work the contacts and cycle the relay. The dB loss initially is all over the place! It appears to settle down with cycles. If not, I will build my own. Insertion loss less than 0.1 dB would be nice. Have a VOM at the fest and measure between Ant and Tx port. If you can, manual press the relay arm. Most likely it will show an OPEN. If so, consider a cleaning will be needed.
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