Hi Rob and all,

FYI - I am using the rig with a Toko HF-240 transverter hence my need
for LSB!

Never mind, its now working! I opened the rig up earlier today, did
some basic checks, nothing obvious - applied switch cleaner to the
mode switch - no change, tapped the relevant crystals (gently), no
change so I left things as they were and put the rig back in my car.

Funny thing was the Velcro holding the rig to the dashboard came loose
and the rig fell 12 inches or so to the floor - low and behold no
damage to the rig but LSB fired back into life! Not sure how long it
will stay this way but it does give a clue to the problem in the first
place.

Thanks for all your help guys, much appreciated.

Paul - g0vht

On May 30, 10:20*am, Rob wrote:
sorry-spammers "" wrote:
Paul wrote:
Just bought an old Mk1 FT-s 290R. All is working well (even the back
light)! but when I switch from USB to LSB the background noise drops
on receive and no output is obtained into a dummy load or any movement
indicated on the rigs own meter?

Not sure I'd really get too worried about it.

Maybe things are different in the UK but there is essentially zero activity on LSB on 2 meters over here in the States -- *everyone* uses upper sideband.

The only thing you need LSB for is working a mode-B satellite transponder..

I think the problem is located in or around the sideband oscillator (Q1013).
It could be the LSB sideband crystal (X01) or the circuitry that switches
the crystals.
First check the "LSB +6.8v" line. *If it does not work, it would be the
mode switch. *I would not apply any "switch cleaner" before checking this.

When this signal is OK, check if the diode is still ok. *I think the most
likely failure is in the crystal X01. *That would probably not be worth
the trouble to replace, except if you want satellite operation.