Yaesu FT7 Dead on 20m - UK Vintage Radio Repair and Restoration Discussion Forum

Sufferinghusban · 7th Apr 2019, 6:45 am

Trying to sort out an old FT7. It operates well on other bands except 20m. When switched to 20m I get the same as if I went to use a Fixed Crystal channel with no crystal in it. I am leaning towards replacing the 28.5Mhz crystal, however finding one seems to be a bit of a problem. Would anyone have any other ideas of what I should look at before trying to obtain another 7 for parts? Thanks in advance. Cheers

G3VKM_Roger · 7th Apr 2019, 12:14 pm

Hi,

There's a chap here in the UK who advertises crystals occasionally in the classified Ads section of Radcom magazine and who I've heard good reports of.

His e-mail is voyjako@gmail.com and I believe he is on ebay but I don't have his user name to hand.

Hope this helps,

Roger

dodgy-dxer · 7th Apr 2019, 4:15 pm

Also Quarzstlab wil make you a crystal

quartslab@aol.com

Dave – GW4AKY

QuartSLab

www.quartslab.com

Email: sales2@quartslab.com

Tel. 020 7100 6357

Mobile: 07496 177 157

73 Fred G4BWP

Biggles · 7th Apr 2019, 9:09 pm

Might be worth checking the original crystal is working by trying to pick up the 28.5MHz signal radiated from it on a scanner or something similar tuned to the frequency. Could save you some trouble.
Alan.

Terry_VK5TM · 8th Apr 2019, 5:18 am

If you have the service manual, page 22 will give you the test point (TP1901 on the Local unit) where you can measure with an RF probe for a 50mV signal in each band.

If you have no signal, then either the crystal is crook or it's associated trim cap is faulty (there can be other causes but they are the two most common).

dodgy-dxer · 8th Apr 2019, 8:31 am

If you dont there is a nice copy but for the FT7B here

http://www.radiomanual.info/schemi/Y.../FT-7_user.pdf

73 Fred
G4BWP

Quote:

Originally Posted by Terry_VK5TM

If you have the service manual, page 22 will give you the test point (TP1901 on the Local unit) where you can measure with an RF probe for a 50mV signal in each band.

Terry_VK5TM · 8th Apr 2019, 12:31 pm

I've got the FT7 one but is too big to post here.

Let me know if you need a copy.

MrBungle · 8th Apr 2019, 1:31 pm

I'd ram another crystal (any old thing - 10mhz - 16mhz) in there and see if it works or not first. Might be another component in the oscillator. Old trimcaps are notorious for going wonky.

Peter.N. · 8th Apr 2019, 4:14 pm

I had this problem on 40m on an FT101 and it was a crystal failure.

Peter

7th Apr 2019, 6:45 am	#1
Sufferinghusban Triode Join Date: Apr 2019 Location: Nowra, New South Wales, Australia Posts: 10	Yaesu FT7 Dead on 20m Trying to sort out an old FT7. It operates well on other bands except 20m. When switched to 20m I get the same as if I went to use a Fixed Crystal channel with no crystal in it. I am leaning towards replacing the 28.5Mhz crystal, however finding one seems to be a bit of a problem. Would anyone have any other ideas of what I should look at before trying to obtain another 7 for parts? Thanks in advance. Cheers

7th Apr 2019, 12:14 pm	#2
G3VKM_Roger Heptode Join Date: Jun 2012 Location: Southeast Norfolk, UK. Posts: 773	Re: Yaesu FT7 Dead on 20m Hi, There's a chap here in the UK who advertises crystals occasionally in the classified Ads section of Radcom magazine and who I've heard good reports of. His e-mail is voyjako@gmail.com and I believe he is on ebay but I don't have his user name to hand. Hope this helps, Roger

7th Apr 2019, 4:15 pm	#3
dodgy-dxer Heptode Join Date: Mar 2008 Location: Newmarket, Suffolk, UK. Posts: 612	Re: Yaesu FT7 Dead on 20m Also Quarzstlab wil make you a crystal quartslab@aol.com Dave – GW4AKY QuartSLab www.quartslab.com Email: sales2@quartslab.com Tel. 020 7100 6357 Mobile: 07496 177 157 73 Fred G4BWP

7th Apr 2019, 9:09 pm	#4
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Yaesu FT7 Dead on 20m Might be worth checking the original crystal is working by trying to pick up the 28.5MHz signal radiated from it on a scanner or something similar tuned to the frequency. Could save you some trouble. Alan.

8th Apr 2019, 5:18 am	#5
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,339	Re: Yaesu FT7 Dead on 20m If you have the service manual, page 22 will give you the test point (TP1901 on the Local unit) where you can measure with an RF probe for a 50mV signal in each band. If you have no signal, then either the crystal is crook or it's associated trim cap is faulty (there can be other causes but they are the two most common). __________________ Terry VK5TM https://www.vk5tm.com/

8th Apr 2019, 12:31 pm	#7
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,339	Re: Yaesu FT7 Dead on 20m I've got the FT7 one but is too big to post here. Let me know if you need a copy. __________________ Terry VK5TM https://www.vk5tm.com/

8th Apr 2019, 1:31 pm	#8
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Yaesu FT7 Dead on 20m I'd ram another crystal (any old thing - 10mhz - 16mhz) in there and see if it works or not first. Might be another component in the oscillator. Old trimcaps are notorious for going wonky.

8th Apr 2019, 4:14 pm	#9
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Yaesu FT7 Dead on 20m I had this problem on 40m on an FT101 and it was a crystal failure. Peter