[Johnson] Johnson 500 Power Supply RY302 Relay Needed

[Rodger]

If you cannot get a mechanical replacement you can use a capacitor and 
resistor to turn any DC relay into a fast make slow break replacement.  
This information is covered in the Desk KW manual (available from BAMA) 
and other sources, I had to add an RC network to the external antenna 
switch box I built for my Desk KW.  Of course standard AC relays can 
also be so modified by the addition of a rectifier diode and possibly a 
series resistor before the RC network.

I am hoping to get a chance to fire up my 500 today and I will see if 
there is a readily detectable delay in the RY302 break.  The RC network 
I put into the Desk KW antenna switch box has about a 1/8 second delay 
on break and the delay is clearly audible.

73, Rodger WQ9E

Craig C. Heaton wrote:
> To All,
>
> Haven't been down this road yet, but I can see where Roger is going. I'd
> like to have a spare RY302 for my 500! According to the manual it is a fast
> make-slow break relay. Looking at the schematic, I don't see a RC circuit on
> the this dc relay to delay it's opening. So, it might be a mechanical
> thing??? The delay is needed to allow time for RF power to decay, the HV
> relay opens first-RF decays; then RY302 opens, the exciter goes quite and
> the receiver can come on line without damage to the front end.
>
> On my 500 I think RY302 doesn't delay anymore. Can only hear one click from
> RY302 & RY303. So I added a DPDT delay relay to keep the receiver off line
> (muted) for a fraction of a second.
>
> 73's
> wd8kdg
> Craig
>
>
> Hi, Roger,
>
> I don't have an original relay, but you can get a  4 pole, 115V DC relay
> from Potter Brumfield. Mouser has them and I suspect Newark or Allied as
> well. That's what I did and it works great. Actually the new relay is a
> better one than the original, it fits in the same space and is a lot
> quieter. Unfortunately I don't remember the part number of the relay but
> it's a pretty common variety.
>
> Good luck!!
>
> Ed, KØBKA
>
>
>   
>> I imagine it is unlikely to find one but does anyone have one of the 4 pole
>> 115 vdc relays identified as RY 302 as is used in the Johnson 500 power
>> supply?
>>
>> I can use a 3 pole and am presently doing so losing only the receive mute
>> contacts which can be picked up from a set of external contacts on the
>> coax relay, but...I'd like to make it "original" if at all possible.
>>
>> TNX, Roger, NJ2R
>>     
>
>
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