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YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 00:41
by gerald123
hi lads ,just got my self one of the abouve recevers......my problem is the band selector. as an example, if i select 5 it shows 3 for about ten seconds, then goes to 5 but it is a pain just waiting for it to change.....HELP
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 13:19
by Admiral
Have you tried switch cleaner on the band selector?
Sorry, best input I can offer as a non-techie.
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 14:36
by gerald123
Admiral wrote:Have you tried switch cleaner on the band selector?
Sorry, best input I can offer as a non-techie.
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 20:54
by gerald123
Admiral wrote:Have you tried switch cleaner on the band selector?
Sorry, best input I can offer as a non-techie.
thanks for that ,but yes I have tried switch cleaner.....no joy
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 21:18
by ChrisCSL
So ... the person you bought it off.
Did it do the same for him?
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 21:41
by gerald123
yes it did the same for him. just thought it would be a easy fix .for 30 pounds pluss postage ........not bad I thought there is not a mark on it, and it looks like new good audio, 12 channel memory fitted...just that one problem with switch.
Re: YAESU FRG -7700 RECEVER
Posted: 01 Nov 2014, 22:12
by ChrisCSL
gerald123 wrote:yes it did the same for him. just thought it would be a easy fix .for 30 pounds pluss postage ........not bad I thought there is not a mark on it, and it looks like new good audio, 12 channel memory fitted...just that one problem with switch.
Fair enough. So at least he must have been honest, and you bought it with an annoying minor fault.
30 quid isn't bad, they were a nice reciever in the day.
Re: YAESU FRG -7700 RECEVER
Posted: 02 Nov 2014, 00:02
by gerald123
ChrisCSL wrote:gerald123 wrote:yes it did the same for him. just thought it would be a easy fix .for 30 pounds pluss postage ........not bad I thought there is not a mark on it, and it looks like new good audio, 12 channel memory fitted...just that one problem with switch.
Fair enough. So at least he must have been honest, and you bought it with an annoying minor fault.
30 quid isn't bad, they were a nice reciever in the day.
yes like I said it is working great...I am just hoping some one will come on here and tell me how to correct the fault .......
please
Re: YAESU FRG -7700 RECEVER
Posted: 02 Nov 2014, 06:45
by 26TM944
Hi,
These are proper old now but have a look around the MC14504 as it's likely to be flaky, the bands are selected by BCD and there are a fair amount of discrete components on the board that can by now have aged to a point where they are no longer stable, leaky diodes and the like. You've got the MB8718 which sits after the level converter, that could be getting moody as well.
Have you done any poking about with a knitting needle to see if anything responds to movement? Does the radio vary in frequency when the fault appears or only the counter?
There was a scrapper on ebay a while ago if still about might be good for spares and of course
https://groups.yahoo.com/neo/groups/FRG-7700/info is going to be a goldmine for info
Good luck.
Steve
Re: YAESU FRG -7700 RECEVER
Posted: 02 Nov 2014, 12:44
by gerald123
26TM944 wrote:Hi,
These are proper old now but have a look around the MC14504 as it's likely to be flaky, the bands are selected by BCD and there are a fair amount of discrete components on the board that can by now have aged to a point where they are no longer stable, leaky diodes and the like. You've got the MB8718 which sits after the level converter, that could be getting moody as well.
Have you done any poking about with a knitting needle to see if anything responds to movement? Does the radio vary in frequency when the fault appears or only the counter?
There was a scrapper on ebay a while ago if still about might be good for spares and of course
https://groups.yahoo.com/neo/groups/FRG-7700/info is going to be a goldmine for info
Good luck.
Steve
Re: YAESU FRG -7700 RECEVER
Posted: 02 Nov 2014, 13:11
by gerald123
thanks ,steve no I have not opened it yet because I did not know what to look for, but now I will ........ where abouts on the board is the [ MC14504 ] is it clearly marked........the frequencie is stable but like I said for example if the band selector in on 5 MHz and you then select 6 MHz it takes about 10 seconds if not more to change. but when it changes it is stable.
Re: YAESU FRG -7700 RECEVER
Posted: 03 Nov 2014, 19:14
by gerald123
26TM944 wrote:Hi,
These are proper old now but have a look around the MC14504 as it's likely to be flaky, the bands are selected by BCD and there are a fair amount of discrete components on the board that can by now have aged to a point where they are no longer stable, leaky diodes and the like. You've got the MB8718 which sits after the level converter, that could be getting moody as well.
Have you done any poking about with a knitting needle to see if anything responds to movement? Does the radio vary in frequency when the fault appears or only the counter?
There was a scrapper on ebay a while ago if still about might be good for spares and of course
https://groups.yahoo.com/neo/groups/FRG-7700/info is going to be a goldmine for info
Good luck.
Steve
thanks for the link steve
Re: YAESU FRG -7700 RECEVER
Posted: 03 Nov 2014, 23:49
by gerald123
hi, checked all inside the radio with a magnifying glass every thing seems ok no leaking diodes no dirt no flaking mci4504 it is all like new as far as I can see. had a look to see if anything loose ......nothing responding to movement....
Re: YAESU FRG -7700 RECEVER
Posted: 05 Nov 2014, 21:10
by bigbassman
Re: YAESU FRG -7700 RECEVER
Posted: 05 Nov 2014, 22:21
by gerald123
thanks for that bigbassman