Golden Eagle 750 " relay help"

[Danzik]

Hi guys I am wanting to replace a golden eagle 750 keying relay. This is the black box linear. The relay has part number ITT 4ZB-CR or possibly 35577. I have been unable to locate one with this part number and the other thing that is confusing me is it says it's 24 VAC ‍ ? When I test the power that engages the relay in the linear I get around 17 VDC not AC so can someone enlighten me on what's going on here and a possible relay part number that would replace this old one ? Thanks

 

[nomadradio]

A wider shot of the relay with some view of it's mounting and the surroundings might help. It looks for all the world like the Potter and Brumfield relay (TE Connectivity) we use for a variety of replacement jobs. Is it soldered into a printed circuit board?

That's what I meant about surroundings.

Got no joy trying to cross-ref the numbers on it.

The 24 Volt AC was a dodge to save a few bucks. A 12-Volt DC relay will work fine. The 17 Volts you measured will drop a few Volts when the relay coil draws current, and the keying transistor also subtracts about a Volt from the total that reaches the relay coil.

Using a relay rated for AC voltage roughly twice the DC voltage you'll use usually works for intermittent duty. It's not a good idea for a relay that's closed continuously for a long time.

I'll see if I have any pics of that model on file next time I'm at the shop.

73

 

[Danzik]

A wider shot of the relay with some view of it's mounting and the surroundings might help. It looks for all the world like the Potter and Brumfield relay (TE Connectivity) we use for a variety of replacement jobs. Is it soldered into a printed circuit board?

That's what I meant about surroundings.

Got no joy trying to cross-ref the numbers on it.

The 24 Volt AC was a dodge to save a few bucks. A 12-Volt DC relay will work fine. The 17 Volts you measured will drop a few Volts when the relay coil draws current, and the keying transistor also subtracts about a Volt from the total that reaches the relay coil.

Using a relay rated for AC voltage roughly twice the DC voltage you'll use usually works for intermittent duty. It's not a good idea for a relay that's closed continuously for a long time.

I'll see if I have any pics of that model on file next time I'm at the shop.

73

Hi Nomad, yes it is soldered into the circuit board, however I think I want to install a socket into the board for ease of removal later so think I will use a relay with the flat pins instead. It is a 14 pin relay and I will get you a wider photo later today however not sure if that will help or not, I am installing this relay in a box that has a missing one the photo is from my other linear that has one in place and is working. Thank you !

 

[Danzik]

I ordered a Omron MY-4 12vdc today, I would think that should work out ok

 

[nomadradio]

should work out ok

Probably.

For a while.

Pretty sure the contacts in that one are rated for about half the current of the original. The MY4 has 5 Amp contacts. The old one is probably rated at 10 Amps per contact.

The full-size relay I use is TE Connectivity type KUP-14D15-12.

Mouser stock number is 655-KUP-14D15-12

I know they sell a socket to fit that one, and it has pc board pins. Good chance the pins on that socket will line up with the holes in the pc board.

Found it! Part number is 27E046.

Mouser stock number is 655-27E046

As in "E-zero_forty-six"

Might be easier than adapting the smaller "ice-cube" size MY4 relay.

73

 

[Danzik]

Probably.

For a while.

Pretty sure the contacts in that one are rated for about half the current of the original. The MY4 has 5 Amp contacts. The old one is probably rated at 10 Amps per contact.

The full-size relay I use is TE Connectivity type KUP-14D15-12.

Mouser stock number is 655-KUP-14D15-12

I know they sell a socket to fit that one, and it has pc board pins. Good chance the pins on that socket will line up with the holes in the pc board.

Found it! Part number is 27E046.

Mouser stock number is 655-27E046

As in "E-zero_forty-six"

Might be easier than adapting the smaller "ice-cube" size MY4 relay.

73

If I am not mistaken the old one was 3amp if ya can even see that in the photo but a larger one would be much better if it would fit beside the preamp relay I will check those out !. Also do you know if they still make these lights????

 

[nomadradio]

The original sure is an "ice cube" package relay. The original Potter and Brumfield prefix for this style was "KH". Literally dozens of vendors have made that style relay.

Finding a new-fangled LED in a 1/2-inch hole fixture might be easier than an incandescent light like that one.

A longer look at that picture leaves me remembering a relay underneath the chassis deck between the two coax sockets. Might just be remembering a different linear.

73

 

[Danzik]

The original sure is an "ice cube" package relay. The original Potter and Brumfield prefix for this style was "KH". Literally dozens of vendors have made that style relay.

Finding a new-fangled LED in a 1/2-inch hole fixture might be easier than an incandescent light like that one.

A longer look at that picture leaves me remembering a relay underneath the chassis deck between the two coax sockets. Might just be remembering a different linear.

73

There is a 3 pole and another 2 pole under the board on these that handle the HV transformers. Someone had modified this one I am working on and had a larger 3 pole in place of the ice cube however it is not functioning correctly is why I want to put it back to original and see what happens. Thanks

 

[nomadradio]

Knock knock!

Who's there?

Elvis.

Elvis who?

How soon we forget.

Been 8 years since the last one of these we fixed up, pretty sure. Had forgotten now many relays that one has in it. There was no preamp in the one below, but this model has more relays than you would expect.

Didn't snap a pic of the antenna relay on this one.

Dern!

73

 

[Danzik]

Yep, got the socket and relay installed and the other two on the back configured properly and she is working great ! I guess those lights by the switch also come apart which I didn't know so I just replaced the bulb, made it simple ! Been replacing the meter lamps also, thank you !

 

[xxjoker21xx]

Hi guys I am wanting to replace a golden eagle 750 keying relay. This is the black box linear. The relay has part number ITT 4ZB-CR or possibly 35577. I have been unable to locate one with this part number and the other thing that is confusing me is it says it's 24 VAC ‍ ? When I test the power that engages the relay in the linear I get around 17 VDC not AC so can someone enlighten me on what's going on here and a possible relay part number that would replace this old one ? Thanks


View attachment 70187

Its reading DC because there is Always a Diode inline with the Relay input or it Won't unkey.. Also sounds
like your keying transistor is shorting or one of the Caps shorting out in the Amp.

 

[Danzik]

Its reading DC because there is Always a Diode inline with the Relay input or it Won't unkey.. Also sounds
like your keying transistor is shorting or one of the Caps shorting out in the Amp.

It's working just fine now, the linear has all new HV caps, not really sure what was keeping it keyed up before, it only did it when I cranked up the variable power but for some reason I believe it was the brown wire coming from the transformer that goes to the power supply board as it seems like I had issues with this wire popping loose before, I cleaned it up with a Dremel wire brush and pushed it into the connector with more force and haven't had a issue since.

 

[Danzik]

That brown wire there to be exact

 

[Danzik]

Well unfortunately I had this linear sitting around for awhile until I got nice new screws for the cabinet and put them all in and set it up on my radio desk and keyed it up a few times with my golden eagle mark III and it was working fine then all of a sudden it wasn't, now it has no power output at all so I put it back on the bench took the cover off to try to find out what's going on with it and as of right now I am lost ! All 3 relays are engaging I even did a continuity test on the contacts to make sure they are making contact and they are, I have high voltage at over 1000 vdc on the caps when keyed but no power out, I notice I have no voltage on pins 2 the cathode when keyed, shouldn't I have ? I have removed the 1000pf 1kv capacitor that comes from the rf in coax and goes to the cathodes and tested it for shorts and tested it in a capacitor tester and it came back good. The only voltage I could find on the bottom pins of the tubes was filament voltage, and negative bias the finals had -111vdc of bias on pins 5 and 9 which seems high ? Anyone have any advice on what I should check from here ? Was thinking maybe I should replace all of the coupling capacitors maybe they might be due anyways, not sure what to try or check next any advice would be appreciated, thanks

 

[Danzik]

Tubes have also been tested and are very good I should add