Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: FT-101E recap, now TR is sticky  (Read 5836 times)
N2LK
Member

Posts: 71




Ignore
« on: August 07, 2013, 01:41:01 PM »

Picked up a very nice condition FT-101E a month ago and enjoying it. I picked up a set of replacement Electrolytic Caps as a fun and long term upgrade project and did the first board last nite. Did the Power Regulator board and worked well...puts out full 110 watts on 15 meters now, only did about 70 before.

But now I am getting intermidant T/R problems...like the delay in CW is sticking...I can fiddle with the relay delay setting and will work find for awhile, then it will stick again.

I am thinking of cleaning the RL-1 relay, but wanted others more expert opinion...

Any thoughts appreciated. Have to recap the AF board of course yet, but before doing that wanted to see what others thought.

73
N2LK
Logged
AB1MN
Member

Posts: 47




Ignore
« Reply #1 on: August 07, 2013, 02:03:45 PM »

Well, let me ask the obvious question first. Did it work ok before doing the recap? When troubleshooting something that used to work and now doesn't, I am always a bit suspicious of the last thing that was done.

Is it possible that you might have one of the electrolytics in backwards (reversed polarity)?

Bob
Logged
N4NYY
Member

Posts: 4816




Ignore
« Reply #2 on: August 07, 2013, 02:16:37 PM »

Well, let me ask the obvious question first. Did it work ok before doing the recap? When troubleshooting something that used to work and now doesn't, I am always a bit suspicious of the last thing that was done.

Is it possible that you might have one of the electrolytics in backwards (reversed polarity)?

Bob

Very good advice. I typically recap one cap at a time. It is easy to not screw it up that way.
Logged
N2LK
Member

Posts: 71




Ignore
« Reply #3 on: August 07, 2013, 02:22:06 PM »

Yup, good question.
Yes of course it worked before I started the recap! But it had to be fixed!!~ Grin

But yes, TR switching was fine. I checked 3 times the cap polarity and did one at a time. All else is working fine, even more power on 15 meters...

I suspect something on the AF board is now acting up due to the change.

I have made 3 qso's on it since last nite, then it will stick...odd...

fun though..
Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #4 on: August 07, 2013, 02:41:13 PM »


But now I am getting intermidant T/R problems...like the delay in CW is sticking...I can fiddle with the relay delay setting and will work find for awhile, then it will stick again.


 With this information, my first suspect is a dirty or dry delay potentiometer. 

With the rig off, spray a wee bit of Deoxit or equivalent into that pot, then, while still wetted, turn the pot from end to end fie to ten times. 

Then set it back where it was and turn the rig on, try adjusting the delay again and see if the problem persists.  It very well could solve this.


73
Logged
N2LK
Member

Posts: 71




Ignore
« Reply #5 on: August 07, 2013, 07:12:15 PM »

OK, pulled out the AF board and did a thorough cleaning...just as recommended...put the board back in and so far, so good...nice steady TR operation...see if it changes....

Still have to pull that AF board out and change out 25 Electrolytics, but that is for another day....

Thanks as always for the ideas and help..
73
Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #6 on: August 08, 2013, 07:26:53 AM »


Still have to pull that AF board out and change out 25 Electrolytics, but that is for another day....



Blanket electrolytic replacement is somewhat all the rage these days, but the truth here is that the Japanese electrolytics as found in your '101 are of superior quality and may just last a long, long time.  

Of course, one should do a visual examination, perhaps using magnifier, looking for signs of bulging or leakage of fluid, such caps, if found, should be replaced.  But the good old Japanese caps in the many '101s that have passed across my testbench (and other pieces of EIAJ gear from that era, to include stereo.hifi stuff, tape recorders, etc.) really don't suffer from the dried out electrolytic problems that started with Chinese made knockoff caps a full two to three decades later.  

Those old Japanese electrolytic caps with the gray heatshrinkable covers on 'em, "Elna" and other brands, are really quite good, comparable with the US Sprague stuff, also from an era long gone.  

And, the analog circuits they were used in such as you find in the '101 don't hammer the caps such as happens in modern designs where switching, "hammering" of the caps etc. takes its toll on the ESR of the cap.  

Still, hams replace all electrolytics found, thinking that they've done something good, I've got a feeling that that the only good thing that really comes from that way of thinking is the amount of money lining the pockets of those who sell new electrolytic caps.  

At the pro testbench, we cannot do that to our customers, in my view such would be overly expensive and downright criminal.  If I find a faulty component, I replace it.  If the component is not found to be faulty, I leave it alone.  Having no crystal ball, I cannot tell a customer that a perfectly good and known working component "needs" to be replaced because it might go bad in future.  Hell, you could say something like that regarding every component in the darn things...

That said, I do pay special attention to the relatively few capacitors found on the '101's 6V regulator board.  Here is a place where replacing a small amount of electrolytics now may indeed be a good thing to do, since the IC regulators used on some models are now unobtanium.  That's not a huge problem, as we can nowadays rework that board using modern three-terminal regulators, making it simpler as to component count and actually a bit more stable anyway.

AF board, not so much.  The electrolytics there are not taking a beating. 

73
« Last Edit: August 08, 2013, 07:31:28 AM by KE3WD » Logged
N4NYY
Member

Posts: 4816




Ignore
« Reply #7 on: August 08, 2013, 11:42:09 AM »


Still have to pull that AF board out and change out 25 Electrolytics, but that is for another day....



Blanket electrolytic replacement is somewhat all the rage these days, but the truth here is that the Japanese electrolytics as found in your '101 are of superior quality and may just last a long, long time.  


73

I know 2 fellow hams from my radio club that had their 101s pop and go dead. Both were caps. I cannot say if this is common, but the caps on these are 35-40 years old.
Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #8 on: August 08, 2013, 02:12:48 PM »


I know 2 fellow hams from my radio club that had their 101s pop and go dead. Both were caps. I cannot say if this is common, but the caps on these are 35-40 years old.


So replace the bad cap, check the others for visual signs and move on. 

I also said this, in the same post, but you decided not to quote that: 

Quote
Of course, one should do a visual examination, perhaps using magnifier, looking for signs of bulging or leakage of fluid, such caps, if found, should be replaced.

Also said this: 

Quote
hat said, I do pay special attention to the relatively few capacitors found on the '101's 6V regulator board.  Here is a place where replacing a small amount of electrolytics now may indeed be a good thing to do, since the IC regulators used on some models are now unobtanium.

Citing two capacitor failures does not make any kind of statistically valid trend.  Of course there will be some failures.  Odds are very good, though, that the vast majority of the millions of '101s out there in the world are still functioning perfectly well with original caps in them. 


73

Logged
N4NYY
Member

Posts: 4816




Ignore
« Reply #9 on: August 08, 2013, 02:28:09 PM »


I know 2 fellow hams from my radio club that had their 101s pop and go dead. Both were caps. I cannot say if this is common, but the caps on these are 35-40 years old.


So replace the bad cap, check the others for visual signs and move on. 

I also said this, in the same post, but you decided not to quote that: 

Quote
Of course, one should do a visual examination, perhaps using magnifier, looking for signs of bulging or leakage of fluid, such caps, if found, should be replaced.

Also said this: 

Quote
hat said, I do pay special attention to the relatively few capacitors found on the '101's 6V regulator board.  Here is a place where replacing a small amount of electrolytics now may indeed be a good thing to do, since the IC regulators used on some models are now unobtanium.

Citing two capacitor failures does not make any kind of statistically valid trend.  Of course there will be some failures.  Odds are very good, though, that the vast majority of the millions of '101s out there in the world are still functioning perfectly well with original caps in them. 


73




I think you are way inaccurate when you say that recapping is the rage. If anything, most people do not recap (at least the ones I know). I am one of the few that recaps and am a proponent of it. The radios I recap have all be old and not in good working order. After I recap and align, they seem to work great. Granted, I mostly do restorations. People who do repairs and not restorations, may only change what is needed.

Personally, I have no problem with your method if you are just repairing. But if you are restoring, I wholeheartedly disagree. It's like restoring a classic car and leaving the engine untouched because it simply works and runs.

Saying that, I have never had an FT-101. But 2 individuals that I know with one, blew caps even though they were in constant use. These were not off for 10 or 15 years.

One last thing. I always measure the caps to see what value they are when I pull them out. Most are above tolerance. Many are usually 2x their rated value. But again, these are usually the 30 years or older kind. I should also mention that I have not done a transceiver yet. Mostly SW or AMBC.
Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #10 on: August 09, 2013, 11:17:35 AM »

Saying that, I have never had an FT-101.

Then stay out of it and come back when you've had as many as I have had, when you have repaired as many more as I have, but I warn you, by the time you have gained that amount of experience I'll probably be dead and buried, kid. 

Quote
One last thing. I always measure the caps to see what value they are when I pull them out. Most are above tolerance. Many are usually 2x their rated value. But again, these are usually the 30 years or older kind. I should also mention that I have not done a transceiver yet. Mostly SW or AMBC.

ALL electrolytics are likely to be higher than their printed value.  That's because it is very difficult to nail the capacity of the electrolytic when building one, and such is not necessary, the electrolytic isn't used for critical frequency control. 

You haven't 'done" a transceiver yet, but you have the audacity to attempt to correct the judgement of this old fart who has been there, done that, seen 'em all, used 'em all, repaired 'em all? 

You were born with two ears, two eyes and only one mouth.  Ever wonder why that is the case? 

I post here as a labor of love.  Nothing more, nothing less. 


73
Logged
N4NYY
Member

Posts: 4816




Ignore
« Reply #11 on: August 09, 2013, 12:50:58 PM »

Quote

Then stay out of it and come back when you've had as many as I have had, when you have repaired as many more as I have, but I warn you, by the time you have gained that amount of experience I'll probably be dead and buried, kid.  

Well, then it is a good thing you do not run this forum. Cause I am staying right here. Not sure why your panties are in an uproar, but you should have stayed on the subject of helping him out with his problem. Instead, you have to spew your gospel according to Clark, as to why he should not have recapped.

Fact: He recapped and it is done. Now help him with his problem.

Also, to pin this problem on his recapping, is speculative. You have no idea if the recapping caused the problem, or if it was a sleeping dog that awoke. You are speculating, on a rig you have not even seen, regardless of the thousands you have repaired.

Quote
ALL electrolytics are likely to be higher than their printed value.  That's because it is very difficult to nail the capacity of the electrolytic when building one, and such is not necessary, the electrolytic isn't used for critical frequency control.


Then why bother with tolerances? FWIW, when I measure new ones, they are usually very close to their printed value. I guess you are not an advocate of keeping components within tolerances?

Quote
You haven't 'done" a transceiver yet, but you have the audacity to attempt to correct the judgement of this old fart who has been there, done that, seen 'em all, used 'em all, repaired 'em all?


I did not correct anything. I have a differing opinion on recapping. And obviously, the poster of this thread had the same opinion. You just took a differing opinion personally. And that is a shame. Recapping is recapping. Transceivers or receivers.

Quote
You were born with two ears, two eyes and only one mouth.  Ever wonder why that is the case?  

I post here as a labor of love.  Nothing more, nothing less.


My post was not confrontational. It was a differing opinion. All I said is when I restore, and when I fully restore, I recap. You said you repair, and only replace what is needed. For whatever reason, that caused you to have a conniption. You are a petty man.
« Last Edit: August 09, 2013, 12:55:12 PM by N4NYY » Logged
AC5UP
Member

Posts: 3927




Ignore
« Reply #12 on: August 09, 2013, 05:16:50 PM »

Let's qualify the re-condenser thing........... In the case of small value paper, ceramic, silver mica and other types used in tuned RF / IF stages, hell yes, they should be as close to value as practical. Although, in an oscillator, stability is a greater virture than tolerance accuracy if the circuit can be peaked to the desired frequency. Once you get it there stability keeps it there.

As for electrolytics, the printed rating is often +80% / -20% and that works as well as 'balls on dead accurate' (an industry term) in the typical AC ripple filter. More capacitance doesn't hurt. I like to rebuild with a little extra capacity as it can reduce the potential for hum and a larger cap has more to lose before it needs replacing. So maybe it lasts longer.

BTW: In case you're wondering, I have a stash of bathtub caps and they look great under the chassis of a console set. There are better options today like polypropelene, but back in the day that was a top-of-the-line condenser.
Logged

Never change a password on a Friday                
KE3WD
Member

Posts: 5689




Ignore
« Reply #13 on: August 10, 2013, 07:06:07 AM »

I have also replaced quite a few power supply filter electrolytics with higher capacity than the original.  Only caveat about doing that is to not take it to extremes, to the point where inrush current is taxing other power supply components, such as transformers or rectifiers. 

Such is an old and easy trick for increasing bass response in AF power amplifiers, as one example. 

In the ham stuff, not so much.


73
Logged
N2LK
Member

Posts: 71




Ignore
« Reply #14 on: August 12, 2013, 08:06:25 AM »

I have been quite impressed with the "strenght" of arguments in this thread I started. Having replaced just the regulator board caps thus far, and seeing a significant increase in output power on 15M means I might have done something right (for a change).

But, in pulling off 12 Elna caps, they all look perfectly good to me...

On the AF board, that is another story. There is some kind of Residue on the board, can be melted with a hot iron, I have replaced 3 caps and 2 did not match the rated voltage of the replacements I bought in the "recap kit". I did contact that vendor and he was quite responsive and investigating...

I just replaced the 25V caps with the new 16V rated ones, and stopped at that. The board is back in doing what it does with a problem I am wondering about:

The VOX Delay takes at least 30 minutes to warm up and operate in cw mode. The side tone takes maybe 3 minutes to warmup from turning on the rig before you start hearing it...and it slowing ramps up to the volume set on the board.

Why?Huh?
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!