[TenTec] Orion II sub receiver problem

[Barry Simpson]

I have a very recently acquired late serial number (black knobs) Orion II
which is in immaculate condition outside and inside.

I have not used it very much since I bought it just prior to Christmas but
yesterday I noticed that the sub receiver (standard model sub receiver) was
making intermittent loud crashing noises like receiving static and the sub
S meter was registering those crashes. The rig had been on most of the day
in a fairly warm room.

However, there were no such static crashes as the main receiver was working
perfectly.

Tonight, I took out the sub receiver board and cleaned all the
pins/connectors although I could not see any tarnishing anywhere.

That did nothing to cure the problem which still occurs with the antenna
connected to a dummy load.

It does not seem to occur immediately when the rig is switched on from cold
but it gradually gets worse as it warms up.

I have not identified anything specific to trigger or make the crashes
worse by tapping on components and screening boxes and wiggling capacitors
and connecting leads.

Before I start dismantling the rig and investigating further, I wonder if
anyone can identify the symptoms and suggest a possible cause.

The only thing I can think of at the moment is the power board capacitor
problem but I do not know how that would result in what I am experiencing.

All and any suggestions and pearls of wisdom would be appreciated.

Thank you in advance.

Barry Simpson  VK2BJ