Yaesu FRG-7700 Band switch advice - UK Vintage Radio Repair and Restoration Discussion Forum

HECTOR63 · 20th Mar 2021, 3:18 pm

I have one recently purchased used and it appears that the Band switch rotary goes round all the way and again with no stop position. I checked against a Kenwood R-1000 and that same change switch will stop at 0 or at the top end of 30.Just wondering if anyone has one of these and can advise, the spindle and knob are all correctly fitted ie-no bends or slipping spindles on the control or the rotary knob due to screw loose etc.

majoconz · 23rd Mar 2021, 4:33 am

I see no reason why there would be a stop. My JRC NRD 515 goes all the way round and there's no stop between 29 and 0 on the MHz rotary switch - it's just a binary encoder.

HECTOR63 · 23rd Mar 2021, 8:30 am

Many thanks Martin, I only asked as it does stop on my Kenwood R-1000 .But at least I know all's okay with the Yaesu in that case just wanted to be sure as learning as I go along, like life-I will get used to it one day

HECTOR63 · 25th Mar 2021, 4:52 pm

Well it seems I may have more serious issues as when the Band selector is tuned the Frequency display does not follow suit to dial coverage with the counting rotation expected when operating the tuning dial it just sits there or may move a couple of digits but that's it! So even if say I select 15 on the Band selector the frequency display will still sit on 1 or 2 and not a lot else. OH well looks like another tin of worms for a project repair

majoconz · 25th Mar 2021, 8:58 pm

I suggest you draw a table of 0 to 29 and then note down what the MHz frequency says for each selection. How's your knowledge of binary coded decimal, BCD, numbering? You may find that you're a digit missing. If it's just a multi wafer switch, then a squirt of switch cleaner may help. On the other hand it may be some weird code like Gray but either way, if it relies on contacts - give it a squirt!

HECTOR63 · 26th Mar 2021, 10:53 am

Many thanks for the advice Majoconz, yes I understand what you mean and shall give that a try and take a look at the binary counts (havent done that for a very long time) but I'm sure that will be good to refresh memories from. Otherwise shall be looking at the manual for test points and get an external frequency counter out and see what that comes back with and look at this issue to try and get a resolve with other issues this one has, just one of those bad eBay buys I guess!

20th Mar 2021, 3:18 pm	#1
HECTOR63 Banned Join Date: Feb 2017 Location: Bedfordshire, UK. Posts: 601	Yaesu FRG-7700 Band switch advice I have one recently purchased used and it appears that the Band switch rotary goes round all the way and again with no stop position. I checked against a Kenwood R-1000 and that same change switch will stop at 0 or at the top end of 30.Just wondering if anyone has one of these and can advise, the spindle and knob are all correctly fitted ie-no bends or slipping spindles on the control or the rotary knob due to screw loose etc.

23rd Mar 2021, 4:33 am	#2
majoconz Heptode Join Date: Jan 2008 Location: Ashhurst, Manawatu, New Zealand Posts: 570	Re: Yaesu FRG-7700 Band switch advice I see no reason why there would be a stop. My JRC NRD 515 goes all the way round and there's no stop between 29 and 0 on the MHz rotary switch - it's just a binary encoder. __________________ Cheers - Martin ZL2MC

23rd Mar 2021, 8:30 am	#3
HECTOR63 Banned Join Date: Feb 2017 Location: Bedfordshire, UK. Posts: 601	Re: Yaesu FRG-7700 Band switch advice Many thanks Martin, I only asked as it does stop on my Kenwood R-1000 .But at least I know all's okay with the Yaesu in that case just wanted to be sure as learning as I go along, like life-I will get used to it one day

25th Mar 2021, 4:52 pm	#4
HECTOR63 Banned Join Date: Feb 2017 Location: Bedfordshire, UK. Posts: 601	Re: Yaesu FRG-7700 Band switch advice Well it seems I may have more serious issues as when the Band selector is tuned the Frequency display does not follow suit to dial coverage with the counting rotation expected when operating the tuning dial it just sits there or may move a couple of digits but that's it! So even if say I select 15 on the Band selector the frequency display will still sit on 1 or 2 and not a lot else. OH well looks like another tin of worms for a project repair

25th Mar 2021, 8:58 pm	#5
majoconz Heptode Join Date: Jan 2008 Location: Ashhurst, Manawatu, New Zealand Posts: 570	Re: Yaesu FRG-7700 Band switch advice I suggest you draw a table of 0 to 29 and then note down what the MHz frequency says for each selection. How's your knowledge of binary coded decimal, BCD, numbering? You may find that you're a digit missing. If it's just a multi wafer switch, then a squirt of switch cleaner may help. On the other hand it may be some weird code like Gray but either way, if it relies on contacts - give it a squirt! __________________ Cheers - Martin ZL2MC

26th Mar 2021, 10:53 am	#6
HECTOR63 Banned Join Date: Feb 2017 Location: Bedfordshire, UK. Posts: 601	Re: Yaesu FRG-7700 Band switch advice Many thanks for the advice Majoconz, yes I understand what you mean and shall give that a try and take a look at the binary counts (havent done that for a very long time) but I'm sure that will be good to refresh memories from. Otherwise shall be looking at the manual for test points and get an external frequency counter out and see what that comes back with and look at this issue to try and get a resolve with other issues this one has, just one of those bad eBay buys I guess!