[Drake] Re: TR-3 Relay same as TR-4C? [Was: Need Relay for T4X-C]

[Garey Barrell]

Doc -

No, the TR-3 used an "open frame" style of relay wired in and mounted 
inside the final cage.   Drake made a refit kit at one time to replace 
the original relay with the one specified below.  I believe John Kriner  
<jkriner at cinci.rr.com>  still has some of those "kits", but someone told 
me they are expensive.

The original relay is very difficult to remove and replace without 
damage, and I would strongly suggest replacing it with the newer relay, 
either with the kit from John or a bracket of your own.  You would still 
have to add the 1.5k series resistor also.

73, Garey - K4OAH
Atlanta

Drake C-Line Service Manual
<http://www.k4oah.com> 



doc wrote:

> Is this the same relay used in the TR-3, please?
>
> Thanks!  doc
>
> Garey Barrell wrote:
>
>> Paul -
>>
>> The "correct" replacement relay is the P&B (Tyco) R10-E1-Y4-V2.5k, 
>> same relay used in the TR-4C, which IS available from Mouser.  You 
>> need to add a 1.5k 1/2W resistor in series with the coil, otherwise a 
>> drop-in replacement.
>> The 15k ohm coil relays were failure prone, primarily because of the 
>> very fine wire needed.  The bobbin would swell,  especially in humid 
>> conditions, stressing and breaking the wire.  This is why T-4XC's 
>> that have been stored in the garage for a while often have a bad 
>> relay!  The 2.5k ohm coil of course uses considerably larger wire.
>> 73, Garey - K4OAH
>> Atlanta
>
>