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 Post subject: Dow Key relays......
PostPosted: Dec Mon 04, 2017 3:00 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 6484
Location: Freeport, LI, New York 11520
Hi Guys....

Are these relays still made these days? I have a collection of them and a few of them also have "outboard" relays as well. Does anyone use them? I know back in the day they were used as antenna switches between the transmitter and receiver and I'm just wondering if they still are used as such.

Tnx...
...Jim

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 3:05 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 813
Location: Santa Rosa, CA
I use these for a number of seperate vintage transmit/receiver
setups. They work fine and without the hassle of dirty or corroded
contacts over time.

Not sure if they are still made but wouldn't be suprised if they are.
Steve W6SSP


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 3:18 pm 
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Dow Key still lives on as part of Dover Corp. but I don't think they still produce the classic old line; high reliability microwave switching is their prime focus now.

I use a few of the old Dow Key units for some rigs, my Viking 500 still uses one. But I have gradually moved away from them as they do require more maintenance as they age both for the main and auxiliary contacts. The most common failure seems to be buildup on the receive side antenna contact with poor sensitivity that is cured by cleaning, I have fortunately yet to have one fail on the transmit side and to some extent the power flow through them helps to self clean. I have also had to clean the aux contacts several times to cure issues of receivers not coming out of standby.

Now for stuff 300 watts and lower I use cube type relays and vacuum relays for high power stuff; at higher power the vacuum relay is much better at avoiding hot switching on make since the control line will cause it to close faster than the plate transformer primary relay and by using a vacuum relay with a DC coil a small electrolytic cap across the coil will provide the slight delay on break required to prevent hot switching during the changeover to receive.

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 3:46 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 6484
Location: Freeport, LI, New York 11520
Tnx fer the replies....

I see that there's an access hole for the internal relay which means that you can burnish the contacts if there not too worn. Were replacements contacts ever offered?

...Jim

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 3:57 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
Kinda dumb but I think this group would understand...Reading about these relays actually gives me a twinge of nostalgia. After graduating from a DPDT toggle switch mounted under the desk to switch my NC-2-40D/DX-20 combo (I shudder now to think about the exposed voltage), I saved up enough to get a very used Ranger and a Dow-Key with the external contacts for muting. The shape of the thing is imprinted and I still get that little thrill when I'm reminded of those early days more than half a century ago.

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 4:05 pm 
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Avery,

My original T/R setup for my novice station was:

1. flip standby switch on front of Hallicrafters SX-62
2. rotate home brew rotary switch that changed antenna from receiver to transmitter
3. turn on Valiant plate switch

Reverse when going from transmit back to receive.

It wasn't too bad as a 14 year old novice but I wouldn't care to try to reliably act as the "human switch sequencer" now.

Other novice notes:

Sending monitor was the hum from the Valiant plate transformer when the transmitter was keyed.
For a quick wake up in the morning (I didn't drink coffee back then) put fingers across key terminals. Keying was done using the -265 volt bias line to the keyer tube; safely current limited but the voltage still created a tingle that most wouldn't enjoy.

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 4:26 pm 
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Joined: Feb Fri 25, 2011 12:57 am
Posts: 1978
Location: 08033 Cherry Hill Jersey
Hams still use these relays UHF, N-type (even old ones) and that's reflected in the hamfest prices. I see them periodically for min of $20 each, and more if they have the external relay tabs attached.

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 5:56 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
rsingl wrote:
Avery,

My original T/R setup for my novice station was:

1. flip standby switch on front of Hallicrafters SX-62
2. rotate home brew rotary switch that changed antenna from receiver to transmitter
3. turn on Valiant plate switch

Reverse when going from transmit back to receive.

It wasn't too bad as a 14 year old novice but I wouldn't care to try to reliably act as the "human switch sequencer" now.

Other novice notes:

Sending monitor was the hum from the Valiant plate transformer when the transmitter was keyed.
For a quick wake up in the morning (I didn't drink coffee back then) put fingers across key terminals. Keying was done using the -265 volt bias line to the keyer tube; safely current limited but the voltage still created a tingle that most wouldn't enjoy.

Rodger WQ9E


Lord, the dumb things we do when we're young... (No, no, not the T/R lashup, the wakeup routine.)

So I have to ask--did you screw up the sequence very often, and what were the interesting results? I'm thinking in particular of flipping the plate switch without putting the rx on standby.... Naaah, you wouldn't have done that. :shock:

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Mon 04, 2017 6:13 pm 
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Avery wrote:

Lord, the dumb things we do when we're young... (No, no, not the T/R lashup, the wakeup routine.)

So I have to ask--did you screw up the sequence very often, and what were the interesting results? I'm thinking in particular of flipping the plate switch without putting the rx on standby.... Naaah, you wouldn't have done that. :shock:


Avery,

I don't recall ever messing up the sequence but it was 42 years ago so the passing of time may have allowed me to repress and forget any bad events :)

I did switch to a relay solution after 3 weeks but continued to use the transformer hum as a keying monitor.

The weirdest thing I had to do with the original novice setup was leave the cover up on my SX-62 receiver so that I could use hand capacitance to fine tune when trying to use the crystal filter on 40 meters. Fortunately for me I upgraded to a SX-101 after a week.

And I only did the wakeup via shock routine once but that instant wakeup is something I won't forget 70 years later if I make it that long. It reminds me of one of the more humorous passages that appears in one of the Tektronix 500 series scope manuals cautioning users that the sawtooth output connector presents over 100 volts and some individuals may find the shock painful. I assume the author had personal knowledge of some colleagues at Tektronix who enjoyed the sensation of over 100 volts exposure :) It probably was an inside joke after someone got across the horizontal sweep output. There are quite a few instances of Tektronix humor in their older manuals and I still consider these manuals the gold standard for excellent technical writing.

The author of the old Tektronix scopes website preserved some of the graphical humor from the early manuals: http://www.reprise.com/host/tektronix/humor/default.asp

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 5:19 am 
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Joined: Oct Sun 15, 2006 12:57 pm
Posts: 5317
I used a Dow relay once years ago, but have been a T/R switch fan ever since. No contacts and hot coffee.

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 1:52 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
rsingl wrote:
...There are quite a few instances of Tektronix humor in their older manuals and I still consider these manuals the gold standard for excellent technical writing.

The author of the old Tektronix scopes website preserved some of the graphical humor from the early manuals: http://www.reprise.com/host/tektronix/humor/default.asp

Rodger WQ9E


I've hung onto Stan Griffiths' encyclopedic compendium of the Tek scopes forever. Not a manual, but clear and succinct, as good tech writing should be.

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Avery W3AVE


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 2:37 pm 
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Avery wrote:

I've hung onto Stan Griffiths' encyclopedic compendium of the Tek scopes forever. Not a manual, but clear and succinct, as good tech writing should be.


Avery,

I have Stan's book also. An early part of my introduction to electronics was my fascination with my father's Tektronix Type 514AD scope which was a very early model. He was a civilian supervisor in the precision measurement lab at Keesler AFB and I had some enjoyable trips tagging along to work with him well before I started the first grade to explore the lab.

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 2:43 pm 
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Joined: Dec Sun 14, 2008 3:33 pm
Posts: 612
Location: Tokyo
I used a miniature DPDT knife switch for about 6 months. The kind they used for the electric chair in old movies. The exposed contacts on that switch taught me there was a good reason people talked about 'RF burns', and not 'RF shocks'.

I was planning to get a Dow Key relay (at $10, a little expensive for a 14 year old in 1964, money better spent on new xtals), but an article appeared in QST that said it was much cheaper, and worked as well, to put a relay in an aluminum box and add coax connectors. The QST recommended relay was about $1.50, the box less than a buck, and I don't remember how much the coax connectors were. I think I'll still do it that way today.

Rob


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 2:50 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
shinkuukan wrote:
...I was planning to get a Dow Key relay (at $10, a little expensive for a 14 year old in 1964, money better spent on new xtals), but an article appeared in QST that said it was much cheaper, and worked as well, to put a relay in an aluminum box and add coax connectors. The QST recommended relay was about $1.50, the box less than a buck, and I don't remember how much the coax connectors were. I think I'll still do it that way today.

Rob


Rob, of course it was cheaper and worked just as well. But you lose that iconic look, which is priceless. (You didn't know that at 14, nor should you have cared. So I forgive you. :?)

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 3:16 pm 
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Mikeinkcmo wrote:
I used a Dow relay once years ago, but have been a T/R switch fan ever since. No contacts and hot coffee.


I have a couple of the Johnson T/R relays and they do make a nice little hot plate but the cats would prefer a bigger surface area. The Siamese cat really loved the top of my Johnson Viking 500 with the warm breeze coming off the fan cooled 4-400A final until one day when the slow release relay didn't slow release causing the Dow Key relay to hot switch which cause the protective arc gap on the final cage to fire. The cat jumped several feet into the air and decided sleeping on top of a potential thunderstorm wasn't a great idea.

I had a similar experience when initially testing my Desk KW after I rebuilt it. When I bought it a prior owner had taken it apart and had all of the panels refinished and it was like putting a kit together. I replaced a couple of wires in the harness that were bad and installed a better switch in place of the mode switch which didn't have as sure of an action as I liked when changing between the various power/operating class choices. I was working in the barn with the cage out of the pedestal and sitting on the outfeed table for my Unisaw. Initial testing went fine and then I switched from CW to phone and the relay that shorts the modulation transformer secondary is VERY loud when the cage is out of the pedestal and before I realized it was just the relay working as intended I jumped in the air and jerked the plug out of the outlet. Further testing and operation went fine but it is good that I didn't have a heart condition or I probably would have been lying dead on the barn floor.

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Tue 05, 2017 3:50 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
rsingl wrote:
...I was working in the barn with the cage out of the pedestal and sitting on the outfeed table for my Unisaw. Initial testing went fine and then I switched from CW to phone and the relay that shorts the modulation transformer secondary is VERY loud when the cage is out of the pedestal and before I realized it was just the relay working as intended I jumped in the air and jerked the plug out of the outlet. Further testing and operation went fine but it is good that I didn't have a heart condition or I probably would have been lying dead on the barn floor.

Rodger WQ9E


Yeah, it took me a while to get used to the emphatic KERCHUNK of my WE Cardmatic when it slams down those pins. Still makes me cringe, in fact. I half expect to see little metal bits all over the floor. I guess it made those WE engineers and techs feel all manly, since they didn't modify the Hickok design for a quieter, gentler engagement.

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Thu 07, 2017 1:26 am 
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Joined: Dec Sun 14, 2008 3:33 pm
Posts: 612
Location: Tokyo
...you lose that iconic look...

Avery, strictly speaking, can a device which sits all day behind the transmitter and is never seen be considered 'iconic'?

OK, interesting topic, c1960 iconic ham gear (excluding tx and rx): D-104 mikes, phone patches, Vibroplex Originals (gray base, not the chrome version), Johnson Matchboxes, inverted Vee 80 meter antennas, ashtrays, labelmakers, Conelrad monitors, Bud and Ameco CPOs...

Rob


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Thu 07, 2017 3:08 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2286
Location: Potomac, Md.
shinkuukan wrote:
...you lose that iconic look...

Avery, strictly speaking, can a device which sits all day behind the transmitter and is never seen be considered 'iconic'?

OK, interesting topic, c1960 iconic ham gear (excluding tx and rx): D-104 mikes, phone patches, Vibroplex Originals (gray base, not the chrome version), Johnson Matchboxes, inverted Vee 80 meter antennas, ashtrays, labelmakers, Conelrad monitors, Bud and Ameco CPOs...

Rob


Of course it can be iconic, hidden or not. If you saw it in silhouette with no identifying information, would you be able to ID it? I think the Dow-Kay qualifies.

A few proposed additions to your list: CE Sideband Slicer, J-38 key, Model 19 and 28 TTY, trap verticals.

How is an inverted V 80m doublet iconic??

You're right, this is fun. Rodger, weigh in!

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 Post subject: Re: Dow Key relays......
PostPosted: Dec Thu 07, 2017 3:23 am 
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Nice list Avery and I would add a nice Telechron mechanical digital clock. Something I wouldn't want anyone to take up but authentic for the 60s would have been an ashtray, today just use it for a soldering iron holder. Of course a proper set of headphones would be good and maybe a period logbook for show.

Let's see what others can come up with. I spent 2 hours last night and another 8 today fighting with Win 10 on my daughter's laptop so my thoughts are so limited that I ended up spending a few minutes drinking a nice cold Dos Equis while watching part of the Minion movie after fixing the PC :) Bourbon would have been better but mixing bourbon and coke together was too technologically challenging after fighting with bits and bytes and although my daughter was wanting to help out in return for fixing her computer I am definitely not asking a 14 year old to mix my bourbon and coke!

Rodger WQ9E


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 Post subject: Re: Dow Key relays......
PostPosted: Dec Thu 07, 2017 12:30 pm 
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Joined: Dec Sun 14, 2008 3:33 pm
Posts: 612
Location: Tokyo
Yes, those digital mechanical clocks! How I wanted one! 'When I grow up...' I thought.

Inverted vees for 80 meters iconic? Yes. They solved the problem of how to squeeze an 80 meter dipole into limited space and they worked great, at least that's what everyone believed and repeated. A c1960 meme.

At least one ARRL HB. An Allied Radio catalog.

Rob


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