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#1
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FT-290R - LSB no output on any band?
Hello all,
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? I may delve in tonight and apply some switch cleaner just in case, any one experienced anything similar I wonder? Any help gratefully appreciated . Thanks Paul - g0VHT |
#2
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FT-290R - LSB no output on any band?
I'd start by checking the mode switch and LSB
oscillator. Steve "Paul" wrote in message ... Hello all, 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? I may delve in tonight and apply some switch cleaner just in case, any one experienced anything similar I wonder? Any help gratefully appreciated . Thanks Paul - g0VHT |
#3
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FT-290R - LSB no output on any band?
In article
, Paul wrote: Hello all, 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? I may delve in tonight and apply some switch cleaner just in case, any one experienced anything similar I wonder? Any help gratefully appreciated . Thanks Paul - g0VHT Look to see if the LSB IF Local OSC's isn't working... |
#4
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FT-290R - LSB no output on any band?
In article
, 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? Paul- I'm not familiar with the 290R. Sideband selection is often done by switching between local oscillator crystals. It may be a bad crystal, a dirty switch, or possibly a problem with a diode switching circuit. If the USB and LSB crystals happen to be plug-in, you could try swapping them to see if the problem swaps or stays at the same switch position. Fred K4DII |
#5
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FT-290R - LSB no output on any band?
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. -- Doug Smith W9WI Pleasant View, TN EM66 |
#6
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FT-290R - LSB no output on any band?
On May 29, 8:39*pm, Fred McKenzie wrote:
In article , *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? Paul- I'm not familiar with the 290R. *Sideband selection is often done by switching between local oscillator crystals. *It may be a bad crystal, a dirty switch, or possibly a problem with a diode switching circuit. If the USB and LSB crystals happen to be plug-in, you could try swapping them to see if the problem swaps or stays at the same switch position. Fred K4DII Thanks for your reply Fred. I plan taking 'the old lady' apart tonight and will work through some of your suggestions. Hopefully it won't be too difficult to trace the fault. Many thanks Paul - g0vht |
#7
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FT-290R - LSB no output on any band?
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. |
#8
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FT-290R - LSB no output on any band?
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. |
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