Pearce Simpson Simba SSB 23 Channel

[Ranch55]

C212 (after power switch) still hooks to your relay coil.

I have had it out of the circuit twice and tested it with a capacitance checker/meter.
It doesn't show any leakage.
Does indicate full value capacitance.
Same with D64 and C211 ...........

My mistake from the first post. I went back and edited all my posts to correct my error.
IT IS ALWAYS THE DC VOLTAGE FUSE .......

 

[Dmans]

I've got some "Honey do's" as well to get started on. Been out of town all last week and I'm waaayyy behind (she says )

73
David

 

[Ranch55]

My mistake from the first post. I went back and edited all my posts to correct my error.
IT IS ALWAYS THE DC VOLTAGE FUSE THAT BLOWS.......

 

[Unit 75]

I was looking at your schematic again. K1 has 12v on the high side and has the low end grounded to pin 3 of the mic jack. Can you check pin 3 on the mic jack and see if you happen to have continuity from that pin to the case? Check it with the relay plugged in and check it with it unplugged. Also check to see if you may have a pinched wire at pin 3 that could be touching the case. Also check ( I think they are 47 ohms) the resistors on the pilot lamps and see if any of those are touching ground. Thanks.

 

[Ranch55]

I was looking at your schematic again. K1 has 12v on the high side and has the low end grounded to pin 3 of the mic jack. Can you check pin 3 on the mic jack and see if you happen to have continuity from that pin to the case? Check it with the relay plugged in and check it with it unplugged. Also check to see if you may have a pinched wire at pin 3 that could be touching the case. Also check ( I think they are 47 ohms) the resistors on the pilot lamps and see if any of those are touching ground. Thanks.

Okay, I can do that.
It will be tomorrow.

 

[Ranch55]

I did check the continuity at PIN 3 to ground ....... nothing there.
Also checked the other two pins also, nothing there either.
Only the channel pilot light has the 47 ohm resistor.

I may just go ahead and install a new electrolytic cap at C212 anyway. I have a lot of those on hand. I just do not believe the issue is that because it seems to be relay connected when the receive circuit is completed thru the relay contacts.
As I said earlier, it's hard to track this issue down, since it is not happening all the time.
I keep looking at the receive circuit because it seems to happen after a period of long use and modulating.
But the fuse blowing happens when in receive mode only. Replace the fuse, it blows immediately.
Pull the relay, (which also disconnects the receive circuit), install new fuse, turn on the power, and the fuse does not blow. Turn off power, install relay, and the fuse will blow.
Let the radio "set" unplugged for a couple of days and then turn it back on and all is well again for a week or so until extended modulation and the issue starts all over again.
I am baffled.

 

[Unit 75]

You checked those 2 caps on the bottom of K1 coil to see if they are shorted internally?

 

[Ranch55]

You checked those 2 caps on the bottom of K1 coil to see if they are shorted internally?

Yes, I actually removed them completely from the board and tested them.
Also removed the large diode and checked it also.

 

[Unit 75]

Hey. How did you make out? Did you find the problem?? Or is it still being stubborn?

 

[Ranch55]

Hey. How did you make out? Did you find the problem?? Or is it still being stubborn?

Okay, don't desert me on this one.
I am still working on this one.
But, I had to set it aside for a few days for a "special" project.
Replacing flooring, shower, and toilet in the guest cabin out here at the ranch.
No one told me there was a problem. I was checking the cabin, as I do about once a month. While in the cabin, the call of nature came on rather suddenly.
I said to myself, what the heck, there is a bathroom right here. No need to go back to the main house.
Well, when I sat down I thought the dang toilet was going to topple over with me on it.
So after a thorough inspection, I am doing the complete bathroom.
Finished the flooring yesterday. Just about ready to install the new shower and new toilet.
So when I get that finished up in the next few days, I'll get back on the Simba and keep you posted.

 

[Unit 75]

All right man. Y'all keeping busy sure enough. Don't work too hard. Sometimes a little break from the radio repair shows new insight to the problem. I hope you get it all figured out.
73's from the Bam.. I will be watching the thread in the future when y'all done with the chores.

 

[Ranch55]

 

[Ranch55]

Okay, I am back into the Simba.
Finally finished up the cabin project about a week ago, complete new bathroom and floor.
Now for the Simba, yesterday I started in on replacing all the electrolytic caps in the whole radio. As of this afternoon, I have 21 out of 34 done. Started on the hard ones and smallest ones.
Have not found any "bad" ones yet, but most of them are way, way out of the original specifications called for.
All that I am installing are audio grade caps.

 

[kopcicle]

What? No flux capacitors ?

 

[Ranch55]

Well heck, got all 34 electrolytic caps replaced.
Did not find any bad ones. Found many that were out of spec. but they did not affect the alignment or the performance of the transceiver.
Now then, back to the original issue, which I have not been able to reproduce on the bench, I'm kind of stuck at this point. The radio is performing just fine at the moment.