Yaesu FT-902DM - UK Vintage Radio Repair and Restoration Discussion Forum

morecider · 6th Sep 2010, 10:05 pm

Hi
Just picked up a Yaesu FT-902DM with its smoothing capacitor
blown out

Where can I find a 500v 100uf Electrolytic capacitor please" only seem to find 250V for sell"
Thank you

Pete

Station X · 6th Sep 2010, 10:18 pm

Here:-

http://www.audiocap.co.uk/ft-100uf--...ytic-309-p.asp

A bit of googling will reveal other suppliers.

Richard675 · 6th Sep 2010, 10:45 pm

Pete,

If you do not know the set's history then maybe it has suffered other traumas. If this set is similar to the 101Z then do check the voltage doubler diodes that create the PA HT. Mine all expired after one of the 6146's flashed over. Hopefully the mains transformer is ok?

morecider · 7th Sep 2010, 2:01 pm

Hi
Thank you for the help finding a capacitor Ideal

I guess theres going to be alot more wrong with it
to blow out that size capacitor

Station X · 7th Sep 2010, 2:18 pm

If you post up an extract from the circuit ie PSU area we can point you to likely suspect components. It's possible that the cap deformed with age and then mains was applied destroying it. This is not uncommon.

Richard675 · 7th Sep 2010, 8:01 pm

....another thing most important to check now is the correct mains fuse has been/was fitted. This is the only item that can protect the mains transformer.

The 902 is a nice rig, well done for sourcing it!

Station X · 7th Sep 2010, 9:22 pm

I suspect that this is the board concerned. I'd advise testing every component on it and reforming or replacing the other similar capacitor.

PEHamel · 8th Sep 2010, 6:58 am

If you blew one of the capacitors, replace them both and the equalizing resistors.
The work to go back and replace the second one after completing the first failure makes the extra cost worthwhile (in my humble opinion).

neon indicator · 8th Sep 2010, 12:33 pm

yes. My previous FT101ZD had aluminium foil on a nail stuffed into the fuse holders. I always check fuses now on stuff I get.

Fortunately I was there and unplugged it before the Transformer was burnt out. A wire on the 6146 grid supply corroded and fell off. One of the 6146s didn't survive.

My current FT101ZD exploded a PSU cap shortly after I got it. It's working fine. I had the loan of the FT90x Transverter for 2m & 70cm for a while, worked fine on the FT101ZD.

The FT102 uses a bunch of un-sealed too cheap relays. Replacing them (they fail) with decent sealed ones is a pain. I don't want an FT102.

6th Sep 2010, 10:05 pm	#1
morecider Retired Dormant Member Join Date: May 2007 Location: Exeter, Devon, UK. Posts: 30	Yaesu FT-902DM Hi Just picked up a Yaesu FT-902DM with its smoothing capacitor blown out Where can I find a 500v 100uf Electrolytic capacitor please" only seem to find 250V for sell" Thank you Pete

6th Sep 2010, 10:18 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Yaesu FT-902DM Here:- http://www.audiocap.co.uk/ft-100uf--...ytic-309-p.asp A bit of googling will reveal other suppliers. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

6th Sep 2010, 10:45 pm	#3
Richard675 Pentode Join Date: Jun 2009 Location: Braintree, Essex, UK. Posts: 170	Re: Yaesu FT-902DM Pete, If you do not know the set's history then maybe it has suffered other traumas. If this set is similar to the 101Z then do check the voltage doubler diodes that create the PA HT. Mine all expired after one of the 6146's flashed over. Hopefully the mains transformer is ok?

7th Sep 2010, 2:01 pm	#4
morecider Retired Dormant Member Join Date: May 2007 Location: Exeter, Devon, UK. Posts: 30	Re: Yaesu FT-902DM Hi Thank you for the help finding a capacitor Ideal I guess theres going to be alot more wrong with it to blow out that size capacitor

7th Sep 2010, 2:18 pm	#5
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Yaesu FT-902DM If you post up an extract from the circuit ie PSU area we can point you to likely suspect components. It's possible that the cap deformed with age and then mains was applied destroying it. This is not uncommon. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th Sep 2010, 8:01 pm	#6
Richard675 Pentode Join Date: Jun 2009 Location: Braintree, Essex, UK. Posts: 170	Re: Yaesu FT-902DM ....another thing most important to check now is the correct mains fuse has been/was fitted. This is the only item that can protect the mains transformer. The 902 is a nice rig, well done for sourcing it!

7th Sep 2010, 9:22 pm	#7
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Yaesu FT-902DM I suspect that this is the board concerned. I'd advise testing every component on it and reforming or replacing the other similar capacitor. Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

8th Sep 2010, 6:58 am	#8
PEHamel Retired Dormant Member Join Date: Feb 2010 Location: Long Beach, Mississippi, USA. Posts: 30	Re: Yaesu FT-902DM If you blew one of the capacitors, replace them both and the equalizing resistors. The work to go back and replace the second one after completing the first failure makes the extra cost worthwhile (in my humble opinion).

8th Sep 2010, 12:33 pm	#9
neon indicator Retired Dormant Member Join Date: Jun 2010 Location: Co. Limerick, Ireland. Posts: 1,183	Re: Yaesu FT-902DM yes. My previous FT101ZD had aluminium foil on a nail stuffed into the fuse holders. I always check fuses now on stuff I get. Fortunately I was there and unplugged it before the Transformer was burnt out. A wire on the 6146 grid supply corroded and fell off. One of the 6146s didn't survive. My current FT101ZD exploded a PSU cap shortly after I got it. It's working fine. I had the loan of the FT90x Transverter for 2m & 70cm for a while, worked fine on the FT101ZD. The FT102 uses a bunch of un-sealed too cheap relays. Replacing them (they fail) with decent sealed ones is a pain. I don't want an FT102.