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Old 02-28-2021, 12:13 PM   #1
steviewonder
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Default Yaesu FT1000MP mk.5 receive issue.

Hoping some knowledgeable persons may know the fix for this problem.
It's the 200W version. Originally,the receive was totally deaf,with a s/c rectifier type diode,along with a cooked pin diode.,a FAIRLY common problem it seems.
Now it receives fine,but the signal can drop after pushing and releasing the PTT switch,sometimes down to nothing at all.It will stay like that,until PTT is pressed again,and rx comes back to life.
There is the odd mention of this on google,but no answers.
There must be a cure,any help greatly appreciated!
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Old 02-28-2021, 03:03 PM   #2
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Default Re: Yaesu FT1000MP mk.5 receive issue.

does it use a relay?
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Old 02-28-2021, 03:44 PM   #3
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Default Re: Yaesu FT1000MP mk.5 receive issue.

RX/TX relay RL6451 bad if it is doing that on all the bands (Tuner Main Unit). It's a sealed unit, so just replace it. Download the service manual and read page 4-1.

If it is only doing that on one or two bands, its one of the low pass filter relays (2 per band) on the LPF board.

Also test antenna A vs antenna B.

Last edited by CapLeaker; 02-28-2021 at 03:54 PM..
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Old 02-28-2021, 04:01 PM   #4
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Default Re: Yaesu FT1000MP mk.5 receive issue.

Thanks for the replies,
Yes it does indeed use a RX/TX relay. I did carefully remove it's housing,and a little Servisol didn't improve things.A little waggle of the contacts made no difference at all,as that's what I was thinking too.It seems to be fine on other bands,just 27mhz seems to be the problem.Must go and check...All the other pin diodes are fine.It does make sense though,as when it goes deaf,it stays the same even upon power on/off.So will replace RL6451.
Back soon ! , And many thanks !
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Old 02-28-2021, 04:24 PM   #5
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Default Re: Yaesu FT1000MP mk.5 receive issue.

if it is only doing it on one or 2 bands, its the one or 2 of the low pass filter relays on the corresponding band.
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Old 03-01-2021, 01:21 PM   #6
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Default Re: Yaesu FT1000MP mk.5 receive issue.

In this radio,the RX/TXrelay is RL1001 on the RF board.Today i replaced the relay,and it's just the same.It seems to become less of a noticeable signal drop,the lower down you go in the bands,at 9Mhz it seems fine, and gets more noticeable from say,22-27.5 mhz.As the signals vary on keying/unkeying,I would not have thought low pass filter relays,as those aren't energised/de-energised on key up,I would have thought. I did see a post,after hours of trawling,and found a chap with the identical problem.
He thought that it worked fine for a day or two after replacing the RX/tx relay,and ended up sending it to Yaesu,where he said they did a modification,but didn't know/explain what that was...It's a interesting one,for sure !
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Old 03-01-2021, 03:54 PM   #7
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Default Re: Yaesu FT1000MP mk.5 receive issue.

Well, I "thought" RL1001 was the RX/TX relay.Completely barking up the wrong tree......You were quite right capleaker..Found RL6451,and it is indeed faulty.Wonder why it's a reed type? I could only find a service supplement,rather than the full service manual,so followed,pretty much,what the guy was saying about his Yaesu...Big Mistake !.
I must have had a "off" day.
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Old 03-01-2021, 04:28 PM   #8
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Default Re: Yaesu FT1000MP mk.5 receive issue.

sh*t happens to everyone... glad you found the problem!
There are full service manuals available for this rig to download on the internet. The other day I found two. I ended up using the larger in size one.
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