[Collins] 32V2 relay issues

[Dr. Gerald N. Johnson]

On Tue, 2009-06-09 at 18:11 -0600, KD0EZS matt matthes wrote:
> how much current is the coil of the relay drawing?? is it possible that the 
> supply is providing the voltage and not the necessary current?  a quick 
> check would be to attach a voltmeter to the coil terminals, engergize the 
> circuit and see if the voltage drops and how much.


That can't happen because by ohms law if the supply can't put out the
current and the resistance of the coil hasn't changed, the supply won't
put out the voltage either.

But the supply may be dropping under load (characteristic of an old
electrolytic on the filter) but WF2U has already reported that the
voltage is 48 volts as specified. He's having the problem, not me.

> ----- Original Message ----- 
> From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
> To: <collins at mailman.qth.net>
> Sent: Tuesday, June 09, 2009 12:40 PM
> Subject: Re: [Collins] 32V2 relay issues
> 
> 
> > On Tue, 2009-06-09 at 11:39 -0500, wf2u at ws19ops.com wrote:
> >> Folks,
> >>
> >> I have a weird problem with my "newly reactivated" 32V2 transmitter.
> >> I acquired the 32V2 about 10 years ago, and only last week I took it
> >> down from the "projects" shelf, to clean it and bring it back to
> >> operational status.
> >> After cleaning the layers of dust off the chassis, tubes, etc., and
> >> applying contact cleaner on the bandswitch and other switches, I did
> >> the almost obligatory conversion to solid-state rectifiers while
> >> disconnecting the HV paths from the transformer filament windings. All
> >> voltages are normal, the transmitter works perfectly - except... The
> >> relay is not pulling in all the way, no matter how I adjust it. A
> >> little motion is evident, but it doesn't pull in all the way. The
> >> voltage on it is within the ballpark (around 50 V, the coil is a 48
> >> VDC coil according to the specs, and measures 2 Kohm)the coil is not
> >> hot. If I bring the armature too close to the coil core, the NC
> >> contacts open, so this is not an option. If I hold the armature
> >> closed, the transmitter works fine as the HV kicks in. Sometimes, but
> >> rarely, the relay stays closed after the manual help. There is no
> >> mechanical binding (although the contacts springiness feels stiff, but
> >> I can't compare it with a working unit), I even put a dab of lubricant
> >> on the hinge/shaft of the armature.
> >> The problem somewhat stumps me, because nothing seems to be wrong...
> >> I used the transmitter on the air last weekend, with great reports,
> >> but it's a two-hand operation, having to use the push-to-talk switch
> >> and with the other hand push the relay with a long insulated
> >> screwdriver.
> >> Anyone had similar experience? Possible cure short of trying to find a
> >> new relay?
> >>
> >> Thanks in advance for any ideas.
> >>
> >> 73, Meir WF2U
> >> Landrum, SC
> >
> > Try a tiny smear of Vaseline or white grease where the armature pusher
> > strikes the contact stack and where each insulation spacer slips. These
> > have to slide a tiny bit and if they are not moving that can make the
> > relay not move well, there isn't a whole lot of power in the telephone
> > style relay which makes it not clatter, but it can be hung up by a bit
> > of friction. Sewing machine oil should be good for the pivots, better
> > than wd-40.
> >
> > -- 

 73, Jerry, K0CQ, Technical Advisor to the CRA
 All content copyright Dr. Gerald N. Johnson, electrical engineer
> >
> >