[Moon-Net] Transco Y type relay 115 VAC coils - use on DC

Chuck Smallhouse w7cs at theriver.com
Fri Jun 7 00:22:12 CEST 2013

I think that Conrad's original question was whether the 115VAC coils 
could be run on 28VDC.  As I recall from years ago(many) to run their 
coils on 115VAC they added a diode pack on the ends of the coils, to 
operate on whatever their basic voltage was.  Maybe more recent 
manufactured Transco Y relays they have do it a bit differently.  I 
would say that the easiest thing to do would try running DC to the 
coil windings and see if they pull in.  You might start at  a lower 
voltage  than 28VDC and work up to that point.  In any case my 
experience, and that of other repliers, is that the Transcos get 
quite warm with continued "on" times.  They probably need to be heat 
sunk.  This heat could also transfer to to a LNA through it's 
connector and tend to increase it's NF, with the elevated temperature.

The only coax relays, I know, that have interchangeable 24/28VDC and 
115VAC coils are the Dow Key DK60  series.

GL es 73,

Chuck,  W7CS

At 08:58 AM 6/6/2013, Michael Barlow wrote:
>I use a heat sink, consisting of a piece of aluminum sheet (mounted 
>via the 2 thru holes), to dissipate some of the heat. I have 
>experienced no actuator problems, during many years of use, at full 
>coil voltage.
>This idea was suggested by W1JR, many years ago, IIRC.
>                                              GL & 73 de Ron  n4gjv
>From: Ted Hartson <awombat at earthlink.net>
>To: conrad at g0ruz.com; moon-net at mailman.pe1itr.com
>Sent: Thursday, June 6, 2013 10:03 AM
>Subject: Re: [Moon-Net] Transco Y type relay 115 VAC coils - use on DC
>I have used many of these and some off spec at DC etc.  They have a 
>plastic actuator that will warp with high heat.  If they are to be 
>held in place over long periods. For long holds like a receive 
>circuit I would consider a two step supply; one aggressive to get 
>good closure then step back to an amount sufficient to hold not not 
>over heat, I use a cap across the supply  with a 100 Ohms or so in 
>front of it, you get a nice snap then the sealing current is set by 
>the R..  I have heard people say that a mounting plate on the base 
>helps disipate heat biuld up.  GL  Ted WA8ULG
>----- Original Message -----
>From: <mailto:conrad at g0ruz.com>Conrad Farlow
>To: <mailto:moon-net at mailman.pe1itr.com>moon-net at mailman.pe1itr.com
>Sent: Thursday, June 06, 2013 6:42 AM
>Subject: [Moon-Net] Transco Y type relay 115 VAC coils - use on DC
>Hello I have a brand new shiny Transco Y type relay that I want to 
>use with my new 6m SSPA. It has 115V AC coils. Can anyone tell me if 
>they can be used with 28V DC? I ask because I have seen a 28V DC 
>version and the coils look physically the same size and I have a 
>recollection that I read somewhere that they could.
>I'd appreciate any info.
>Conrad G0RUZ
><http://g0ruz.com/new/>G0RUZ's new web pages
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