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eHam Forums => Mods And Repairs => Topic started by: W3DBJ on February 01, 2023, 08:25:46 AM

Title: FT290R MK1 Japan Version - only FM working
Post by: W3DBJ on February 01, 2023, 08:25:46 AM
I was given a JDM FT290R (Japanese domestic market version). It has full power out but only FM is working. None of the other mode selections work on TX or RX (there is no audio in RX in any other mode position than FM) although the sidetone does work in CW mode.

Has anyone faced a similar issue with a FT290R, or possibly have a schematic for the Japanese domestic model? It appears visibly different to the old US version I previously owned.

Thanks
Title: Re: FT290R MK1 Japan Version - only FM working
Post by: W1VT on February 01, 2023, 08:35:46 AM
If you have a spectrum analyzer available, I suggest listening for the oscillator signals. 
If one of them fail in a superhet receiver there won't be any signal that makes it to the detector for amplification.
It can be a quick and easy test because you can often pick them up without any galvanic connection to the circuitry.

Title: Re: FT290R MK1 Japan Version - only FM working
Post by: KD7RDZI2 on February 01, 2023, 11:28:45 AM
I once had one for 1 day and then I returned to the seller after testing. In my case the carrier was shifted within the filter so it was transmitting a loud carrier and some basses on both side bands. However if the carrier is far out the filter I think you might have the issue you describe. Probably it will not be difficult to align it. Another possible issue is the SSB filter itself, because of electromigration, if so, replace the IF filter which is used in the ssb mode. My 2 cents, inflation adjusted  ;D
Title: Re: FT290R MK1 Japan Version - only FM working
Post by: MW1DSB on February 13, 2023, 07:25:14 PM
I have service manual for ft 290r & 290r MKII  if you can send me your email I'll send them over
Title: Re: FT290R MK1 Japan Version - only FM working
Post by: W3DBJ on March 24, 2023, 07:23:22 AM
I once had one for 1 day and then I returned to the seller after testing. In my case the carrier was shifted within the filter so it was transmitting a loud carrier and some basses on both side bands. However if the carrier is far out the filter I think you might have the issue you describe. Probably it will not be difficult to align it. Another possible issue is the SSB filter itself, because of electromigration, if so, replace the IF filter which is used in the ssb mode. My 2 cents, inflation adjusted  ;D

Makes sense! Now that I've had some time to play with it a little more, it seems more like a bad solder issue, but when it's occurring, I do hear the carrier. Sometimes, if I attempt a "slap repair", it works fine. I think I need to find the schematic to track it down.