[Milsurplus] GRC-9 Power supply Question

[WA5CAB at cs.com]

Al,

I usually use (for the coil lamp) 40 watt for 6 volt, 25 watt for 12 volt, 
and 12 watt for 24 volt vibrators. Plus to do the job completely, you need 
at least two lamps. I use 12 watt lamps for the other contacts. Also, 
sometimes it can take several hours before the sulfide layer on the coil contact 
burns through, especially on shunt types.  Procedure is to connect the coil 
drive lamp and (if you only have two lamps) the other lamp to any one of the 
other contacts.  Plug in and run until vibrator starts vibrating and both 
lamps flash.  Then unplug and connect second lamp to third contact.  Plug in 
and run until it flashes.  Repeat until all contacts are cleared.

And FWIW, it is impossible to fix a VB-5 by this method, not that most 
people will ever encounter a VB-5.  The VB-5 has an internal resistor connected 
across the coil contact and you can't get enough voltage across the contact 
to burn through and clear it.  To add insult to injury, every VB-5 I've ever 
worked on had a brittle can that broke up while opening it.  So fixing a 
VB-5 requires another sacrificial vibrator to supply a usable can.

In a message dated 9/20/2010 1:53:33 PM Central Daylight Time, al at ar88.net 
writes: 
> On 9/20/2010 1:46 PM, mac wrote:
> >.....Don't be too surprised if the vibrator for the receiver PS doesn't
> >work the first time you apply power. Common problem requiring opening
> >the can and cleaning the contacts.....
> >
> OK, OK, You've put me over the edged, so I've put the easy solution on 
> my website:
> http://www.skywaves.ar88.net/commrx/Maintenance/Waking%20Up.doc.pdf
> 
> You probably don't have to open the can. I'm about 11 for 11 on saving 
> vibrators this way.
> 
> In Greg's case I beleive you're working with a shunt operated vibrator, 
> so just hook up to pins 1 and 7.
> 
> I'm about 11 for 11 on saving vibrators this way.
> 
> Regards,
> Al
> 


Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480