[TenTec] ORION Synthesizer problem at 18 MHz

[Ulrich Hilsinger]

Hello,

I found a severe problem with my ORION on 17m yesterday evening.

Instead of being tuned to the displayed frequency, the synthesizer for 
VFO A often locks around 560-580 kHz higher (measured with a tektronix 
counter). I.e., instead of 18100 kHz, I operate on 18.660 kHz, while 
18.100 is displayed on the screen.
My first strategy was to make sure that this is not due to a software 
problem:
- I recalled user settings. It helped once, but not at other times.
- I made a recall. No help.
- I made a master reset. Several times. No help.
- I tried to re-install the firmware. Firmware update software braught 
an error message; communication error... Not shure if that has something 
to do with "my" problem. Could be a PC problem.

After trying this for several hours yesterday evening, I switched the 
rig of. After about 30min, I switched it on again - and the frequency 
was ok.
So, this evening I made some further investigations on this problem:
When I first switched the radio on, all was fine. When I had 18.074 on 
the display, I really have been at 18.074 MHz. I let the radio in 
standby mode for about 2 hours. When I came back to the shack right now, 
it has been around 560 kHz too high again. Reset braught no help. I 
cycled it off/on, no help. I switched it off, on again after 15min and 
it was back at 18.1 MHz. After some minutes, it failed again, back at 
+560 or +570 kHz.
The same procedure seems to repeat every time I try it. Actually, it's 
back at the "right" frequency, but no idea for how long time...
There is absolutely NO error indication, and all other bands seem to be 
clear. The faulty carrier at, f.ex., 18.660 kHz, is as stable as all 
"good" signals are.

Did anybody else had this problem ? Obviously it only occurs on 17m, so 
I never remarked a problem during normal contest operation.
My guess is that this is a thermal problem, and probably it is a unique 
failure on my ORION only. It might have been there since ever, due to 
the fact of coming home late (around or after sunset) in the evenings, I 
only operated 17m directly after starting the rig during the last 
months, never after a longer warmup period.

It's somehow frustrating, as 17m is in fine conditions right now (and I 
still need many DXCC entities on that band which I ignored for a loooong 
time..), and I really do *NOT* feel any motivation at all to switch back 
to my old Kenwood TS850 :-(.

Every help is very appreciated.

73,
Ulrich, DH0GHU