Comments on: ICOM 737 Problems http://k5dkz.com/blog/2007/05/18/icom-737-problems/ Ham radio projects and a log of interesting experiences Tue, 06 Jan 2009 05:32:03 +0000 http://wordpress.org/?v=2.5.1 By: g3vbv http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4700 g3vbv Sat, 30 Aug 2008 11:13:32 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4700 40m was dead 7.0 - 7.1 and at other times 7.0 -7.08, now it's dead over the whole 40m band, OK 6.999 and below. My problem was seen on other bands, e.g sometimes on 20m it would stop working below about 14.180, on 17m anywhere from the whole band to below 18.120. Results on all bands varied. I suspect the 40m problem now is wrong capacitance value which means I'll have to take that screening off again and check C35. 40m was dead 7.0 - 7.1 and at other times 7.0 -7.08, now it’s dead over the whole 40m band, OK 6.999 and below. My problem was seen on other bands, e.g sometimes on 20m it would stop working below about 14.180, on 17m anywhere from the whole band to below 18.120. Results on all bands varied. I suspect the 40m problem now is wrong capacitance value which means I’ll have to take that screening off again and check C35.

]]> By: admin http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4699 admin Tue, 26 Aug 2008 22:07:05 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4699 Congradulations!!! I believe you finally got it fixed. If I wore a hat it would be off for you. I am a little embarassed that my 737 is still laying on the repair bench. Your degree of success inspires me to pick up where I left off on the thing. It is sort of nice to have other equipment to use but that is not a good excuse to leave the main rig laying around broken. I have no idea as to why the problems with 40 meters. I will keep it in mind as I work on my radio and let you know if I have any ideas as to what to do with 40 meters. My radio still worked on 40. It had problems on 80 meters down. Still worked on the higher frequency bands. Thanks for letting me know of the progress you made and your success. Congradulations!!! I believe you finally got it fixed. If I wore a hat it would be off for you.

I am a little embarassed that my 737 is still laying on the repair bench. Your degree of success inspires me to pick up where I left off on the thing. It is sort of nice to have other equipment to use but that is not a good excuse to leave the main rig laying around broken.

I have no idea as to why the problems with 40 meters. I will keep it in mind as I work on my radio and let you know if I have any ideas as to what to do with 40 meters. My radio still worked on 40. It had problems on 80 meters down. Still worked on the higher frequency bands.

Thanks for letting me know of the progress you made and your success.

]]> By: g3vbv http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4698 g3vbv Tue, 26 Aug 2008 01:54:52 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4698 Got a feeling I made a mistake with 40m, it's completely dead now. All other bands are fine 3+ days on. Got a feeling I made a mistake with 40m, it’s completely dead now. All other bands are fine 3+ days on.

]]> By: g3vbv http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4676 g3vbv Sun, 27 Jul 2008 02:06:54 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4676 Thanks, I won't be able to get around to doing anything for the next 2 weeks. When I do, I shall note each as I replace them. If problems arise, I will be able to put them back in their proper places. It's a pity it's laid out so it's not really possible to try one at a time. My guess is they have a special setup to allow factory alignment. Thanks, I won’t be able to get around to doing anything for the next 2 weeks. When I do, I shall note each as I replace them. If problems arise, I will be able to put them back in their proper places. It’s a pity it’s laid out so it’s not really possible to try one at a time.
My guess is they have a special setup to allow factory alignment.

]]> By: admin http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4665 admin Mon, 21 Jul 2008 23:14:31 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4665 I still do not know if the ceramic capacitors will fix the problem. At present I am using an old Kenwood TS-120 and have been for the better part of a year it seems. Maybe this week I will finally get the caps installed. The problem is that I do not have the equipment I need to align this thing. I was thinking I could measure the value of the old caps and adjust the new ones to match but I have been chicken to do so. \ Maybe I will just put the rig back together as is (without replacing the caps) just to see if it still works. Who knows, maybe the repair fairies have fixed the problem for me. I still do not know if the ceramic capacitors will fix the problem. At present I am using an old Kenwood TS-120 and have been for the better part of a year it seems.

Maybe this week I will finally get the caps installed.
The problem is that I do not have the equipment I need to align this thing. I was thinking I could measure the value of the old caps and adjust the new ones to match but I have been chicken to do so. \

Maybe I will just put the rig back together as is (without replacing the caps) just to see if it still works. Who knows, maybe the repair fairies have fixed the problem for me.

]]> By: g3vbv http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4663 g3vbv Mon, 21 Jul 2008 00:08:24 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-4663 I presume the capacitor replacements fixed the problem. I'm having similar problems on my IC-737 and I have the replacement capacitors, just that I haven't yet got around to replacing them so far. Hope to tackle that job some time in the next couple of weeks. Nice description, stumbled on it after a few weeks of searching, just needed the right keywords in google --- "Icom 737 problems" found it. I presume the capacitor replacements fixed the problem. I’m having similar problems on my IC-737 and I have the replacement capacitors, just that I haven’t yet got around to replacing them so far. Hope to tackle that job some time in the next couple of weeks.
Nice description, stumbled on it after a few weeks of searching, just needed the right keywords in google — “Icom 737 problems” found it.

]]> By: Frank http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2728 Frank Mon, 11 Jun 2007 00:57:53 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2728 turns out it is not glue. It is wax. It melts as heat is applied to the shields to remove them to obtain access for the repair. Apparently this is a very vibration sensitive part of the transceiver, but then we already knew that. turns out it is not glue. It is wax. It melts as heat is applied to the shields to remove them to obtain access for the repair.

Apparently this is a very vibration sensitive part of the transceiver, but then we already knew that.

]]> By: Frank http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2723 Frank Sun, 10 Jun 2007 17:29:21 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2723 Looks like about three weeks and still no joy. Having the maintenance manual does not help. I took out all the screws holding the troubled circuit board to the radio frame and it still will not come out. Been thinking about what to do now. Finally just tried to very gently force the board off and it came unglued. No, unglued in this case is a good thing. Sucker was held to the frame with a large blog of shoe goo. It will go back the same way. The underside of the board is covered with soldered on shields. That and the multitude of delicate little wires running to delicate little connectors has me convinced there has got to be someone out there making better equipment. Why, my Korean made VCR is put together better than this thing. Finally figured out how to install the new caps. I am assuming that the old caps are set close to optimum. So I will remove them, one cap at a time and use the capacitance checker to measure their value. Then I will set the new, ceramic replacement caps to the same value and install them. One at a time. Then button up and hope for the best. Looks like about three weeks and still no joy. Having the maintenance manual does not help. I took out all the screws holding the troubled circuit board to the radio frame and it still will not come out.

Been thinking about what to do now. Finally just tried to very gently force the board off and it came unglued. No, unglued in this case is a good thing. Sucker was held to the frame with a large blog of shoe goo. It will go back the same way.

The underside of the board is covered with soldered on shields. That and the multitude of delicate little wires running to delicate little connectors has me convinced there has got to be someone out there making better equipment. Why, my Korean made VCR is put together better than this thing.

Finally figured out how to install the new caps. I am assuming that the old caps are set close to optimum. So I will remove them, one cap at a time and use the capacitance checker to measure their value. Then I will set the new, ceramic replacement caps to the same value and install them. One at a time.

Then button up and hope for the best.

]]> By: Frank http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2417 Frank Mon, 21 May 2007 20:27:05 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2417 Got some trimmers ordered. Sprague-Goodman ceramics. Two flavors. Ten each flavor. Ordered from Mouser. 659-GKG20015 is a 5-20pf coded red. 659-GKG30015 is a 6.5-30pf coded green. Comming by FedEx ground. Shipping will probably be around 5 bucks. Parts are only 24 cents each for a parts cost of another 5 bucks. Mouser does not have a minimum order and some super good prices. Got some trimmers ordered. Sprague-Goodman ceramics. Two flavors. Ten each flavor. Ordered from Mouser. 659-GKG20015 is a 5-20pf coded red. 659-GKG30015 is a 6.5-30pf coded green. Comming by FedEx ground. Shipping will probably be around 5 bucks. Parts are only 24 cents each for a parts cost of another 5 bucks.

Mouser does not have a minimum order and some super good prices.

]]> By: Frank http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2409 Frank Mon, 21 May 2007 16:51:42 +0000 http://k5dkz.com/blog/2007/05/18/icom-737-problems/#comment-2409 The 737 worked fine for about 48 hours. This morning we are back to the lower three bands being dead to RX and TX. Need to replaced those trimmers after all. Also, looks like some work has already been done. There are solder splotches on all four corners of the lid shield. The solder is not done very well either. So, need to order the trimmers. A check on the parts available here indicates that there are not enough of the right types and sizes. The 737 worked fine for about 48 hours. This morning we are back to the lower three bands being dead to RX and TX.

Need to replaced those trimmers after all. Also, looks like some work has already been done. There are solder splotches on all four corners of the lid shield. The solder is not done very well either.

So, need to order the trimmers. A check on the parts available here indicates that there are not enough of the right types and sizes.

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