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Title: Coax Relay ID Post by: N1ESE on November 19, 2007, 05:23:25 PM I have a couple of these 110VAC coax relays pictured below. The manufacturer is Dow Key Co..
http://n1ese.qrpradio.com/AM/relay-1.jpg Anyone know what these side terminals are for? http://n1ese.qrpradio.com/AM/relay-2.jpg Thanks - JT Title: Re: Coax Relay ID Post by: W1EUJ on November 19, 2007, 05:26:18 PM Indicators/lamps, additional relays or timing circuits would usually connect to those parallel low current (usually non RF) contacts.
David Goncalves W1EUJ Title: Re: Coax Relay ID Post by: N1ESE on November 19, 2007, 05:30:01 PM Indicators/lamps, additional relays or delay circuits would usually connect to those parallel, non RF contacts. Gotcha, thanks. Any idea how much PEP something like this relay could handle? - JT Title: Re: Coax Relay ID Post by: Pete, WA2CWA on November 19, 2007, 05:44:14 PM see attached
Title: Re: Coax Relay ID Post by: N1ESE on November 19, 2007, 05:50:26 PM That's great Pete, thanks! No mention of how much RF it can handle though. It was pulled out of the Chippewa rack so I'm assuming it can handle a decent amount of power in any event.
- JT Title: Re: Coax Relay ID Post by: W1EUJ on November 19, 2007, 06:35:22 PM http://www.dowkey.com/_pseries_attach/_plk13_1_60a.pdf (http://www.dowkey.com/_pseries_attach/_plk13_1_60a.pdf)
This is a datasheet for a similar model - discontinued 60 Series relay. At >50 MHz, it is rated at 1000 W. I found this through Google, no secret well of RF relay knowledge here. David Goncalves W1EUJ Title: Re: Coax Relay ID Post by: WA1GFZ on November 19, 2007, 06:55:27 PM I would use 1 set of aux contacts for RX mute. The other I would put in series with final Key line so the final will not key until the antenna relay is closed then when you drop the key line the final goes down before you disconnect the antenna. Avoids sparks on the contacts by dry switching them. I have a similar relay on my 160 meter class e rig set up the same way. gfz
Title: Re: Coax Relay ID Post by: Pete, WA2CWA on November 19, 2007, 08:58:44 PM That's great Pete, thanks! No mention of how much RF it can handle though. It was pulled out of the Chippewa rack so I'm assuming it can handle a decent amount of power in any event. - JT I says on the first line of text: for switching RF loads up to 1KW. Title: Re: Coax Relay ID Post by: N1ESE on November 19, 2007, 09:02:34 PM It says on the first line of text: for switching RF loads up to 1KW. "Here's my sign"- JT Title: Re: Coax Relay ID Post by: K3ZS on November 20, 2007, 10:26:06 AM In the days of yore, one set would be used to open the B+ line of the receiver, the another could be used, for example, to turn on a VFO, on-the-air signs, turn on an external modulator or to key an amplifier. If you didn't have enough contacts,
would use them to key another relay that did. Title: Re: Coax Relay ID Post by: VE7 Kilohertz on November 20, 2007, 11:07:59 AM I have been using one of these to switch my 1KW CCA broadcast TX for about 3 years now with no signs of problems. Just make sure to close the relay before applying power, and remove RF before opening. I think I time delayed mine with a cap and diode.
Cheers Paul Title: Re: Coax Relay ID Post by: kb2vxa on November 21, 2007, 08:20:49 AM Hi all, AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
One thing to remember about the venerable Dow Key is mounting it horizontally with the coil up. There is a movable pin and collar assembly on the receiver side (the up side) that drops down and shorts the center pin to ground when the coil is energized. Hey, maybe you didn't know that since you asked what the auxiliary contacts are for, anything you want up to 5A. :) |