[Moon] Anyone know where to find a Vectron 108 MHz OCXO ?

SM3BYA, Gudmund SM3BYA at wannberg.net
Mon Jul 6 21:57:29 CEST 2020


Hello all,

Less than three months before my 13cm high power permit elapses 
(probably for good), the 108 MHz oscillator that is the heart of my LO 
system has gone bad.

It is a Vectron model 228-5354 OCXO that has worked perfectly for 11 
years; it has usually stabilised to better than 10 Hz off 108 MHz in 
about 30 minutes and then stayed put for weeks. But last week I lost a 
sked with F2CT for no good reason and it was only after getting the 
counter out that I found that the LO frequency was off by about 1100 Hz 
and moving around erratically by some 5-10 Hz. After mixing with 12 MHz 
and multiplying by x18 this translates to an offset at 2176 MHz of about 
20 +/- 0.2 kHz.

BTW, the system also generates a 117 MHz signal (108 + 9) that will be 
used as LO1 injection for the 6cm DB6NT transverter under construction. 
There the offset will be almost three times as great, so it had better 
be fixed...

The OCXO case is not warm and the frequency vs. time curve does not 
follow the normal pattern, so either the oven control system and/or the 
heater are faulty. But I don't want to risk opening the unit now - it is 
in a metal case that is soldered shut and will have to be opened with 
the aid of a gas torch at the risk of totally ruining the oscillator 
proper...

So now I am looking for a working 108 MHz OCXO as a quick fix, 
preferably an identical Vectron unit but any 108.0000 MHz OCXO should 
work. I have scoured eBay and a number of surplus dealers' websites with 
no luck. If anyone happens to have one that you can part with or if you 
know where to find one, please email me directly at sm3bya AT wannberg.net!

Thanks and 73

Gudmund SM3BYA



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