[time-nuts] Repair of PRS10 Lamp Assembly
paulswedb at gmail.com
Sun Mar 17 15:59:12 EDT 2013
My 2 cents and it is that. The FRS use a higher voltage say 24 V and on
ignition that drops back. I have also seen on time-nuts older systems that
actually use an ignition voltage to trigger the lamp.
But I agree that it sounds like the RF might be low. The bulb does need to
be heated to get to the right color temperature also.
On Sun, Mar 17, 2013 at 9:03 AM, Bob Camp <lists at rtty.us> wrote:
> Unless the PRS10 is very unusual in it's operation there are two things to
> check early in the debug process:
> 1) Is the oven heating up to roughly the right temperature?
> 2) The lamp is lit by RF energy. If the oscillator / amplifier supplying
> the RF isn't putting out as much as it should (or what it should) the lamp
> will not stay lit.
> I'd bet on number 2 in your case. There are many other possibilities, but
> I'd check those two first.
> On Mar 17, 2013, at 5:22 AM, Dr. Götz Romahn <goetz at g-romahn.de> wrote:
> > dear all,
> > beeing a silent reader of this list for a while, I now ask my first
> > I have obtained a PRS10 that was declared faulty and it is. The problem
> I located in lamp assy.
> > Lamp ignites only after warming up and pushing by a voltage kick from
> abt. 24V to abt 28V on the -24_heat line for some seconds. PRS10 gets
> locked there after and rbmon shows a seemingly healthy unit (see
> attachment). But... within some 15 to 45 minutes later light from lamp
> degrades as seen through "LAMP VIEW" hole in top board as well as AD9
> Photocell I/V going down from 1.68 after ignition to 0.158 and lock is lost
> of course. Since all heating and voltage diagnostics do stay within
> accepted limits I suspect some problem within lamp enclosure (see
> attachment). Your help for further diagnosis and any hints for obtaining
> spare parts would be appreciated very much.
> > Cheers Goetz
> > <PRS10 after
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