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Post by husker on Oct 29, 2019 18:26:22 GMT -5
So I have learned that the guy who claimed the radio had SSB receive and weak AM is lying completely. It had zero receive. I have it at a friends house and on his bench, he has gotten it to receive, but not correctly as the S meter strength is much weaker then his MrkII. Sadly, I looks like this mistake is going to cost some $$$$. But the flipside is hopefully the radio runs for yrs after this
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Post by husker on Oct 15, 2019 22:46:33 GMT -5
The list of things that could do this is pretty short. Comes down to T5 and CR3. Everything else is upstream from where the sideband signal splits off from the AM side. 73 Chris, I decided to start with the new multisection cap and see what voltages I was getting...these don't even look close. 363, 368 and 188.. am I wrong or are these way off?
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Post by husker on Oct 13, 2019 0:44:20 GMT -5
The list of things that could do this is pretty short. Comes down to T5 and CR3. Everything else is upstream from where the sideband signal splits off from the AM side. 73 Thanks for the reply sir! CR3 checks out ok, you think its T5? It's strange, if the AM signal is really strong (like channel 6 was today) the receive is great. But it fades and seems to come back. SSB is awesome. Would a bad T5 explain the s-meter lack of function? thanks again!!
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Post by husker on Oct 12, 2019 19:34:22 GMT -5
And this radio has a Collins filter, I tried jumping that and it made no difference
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Post by husker on Oct 12, 2019 1:17:08 GMT -5
Hi all, the Browning Mark II receiver I recently aquired is very clean but looks to have a small..ok big issue. There is minimal to no AM receive and the S Meter has no movement either. If I switch it to SSB, the receiver springs to life as does the S meter. I have just replaced all the rectifiers and caps including the multi section one. Any thoughts folks? I am getting ready to check all the tubes to see if they are ok. I have cleaned the sockets and replaced the nuvistors (I had a spare set just to see if it helped).
Thanks everyone
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Post by husker on Oct 1, 2019 13:11:49 GMT -5
New project, gonna take a while to restore. But I still need the x100 Trans adapter. Anyone know of any around for sale?
Bob
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Post by husker on Aug 21, 2019 21:56:54 GMT -5
I did find these....are they any good? Thank you for posting this, Husker! This is geared towards the D201A... should it also work the same for the D201? Some, yes but not everyone of them. The A version has some different parts to it.
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Post by husker on Aug 2, 2019 11:13:50 GMT -5
The S-meter's zero setting can be affected by more than one kind of drift. To start, cleaning the zero-adjust pot in the rear will help if that's part of the problem. All rotary controls become noisy eventually. A proper 'control cleaner' is best for controls that get cranked up and down regularly. But considering how seldom the S-meter zero should get turned, a simple non-residue contact cleaner is probably okay to use. The light lube contained in a proper "control cleaner" is there to reduce friction damage to the sliding surfaces inside a rotary control. That 'zero' pot shouldn't get turned all that often. A non-residue cleaner shouldn't shorten its life the way it would for the volume control. That one gets cranked a lot more often than the S-meter zero. The far-left (as seen from the front) 6BA6 tube is what controls the meter. Any oxidation in the tube socket or on the pins of the tube will be trouble. Always a good idea to make sure no parts attached to that tube's socket look overheated. A bad tube could have damaged a resistor years ago. And if the color bands all look fairly bright, that resistor probably has not been overheated. Not a big risk, but always worth a look anywhere in the radio, and not just under that tube socket. We find that simply 'rocking' each tube in its socket while listening to a steady signal will reveal noise from dirty or oxidized surfaces in that socket or on the pins of that tube. We use CRC brand "QD" spray cleaner, directed at the tube's pins with the tube cocked slightly to one side in the socket. The tube gets 'rocked' around in the socket to scrub the contact surfaces. Once that tube remains quiet while it is 'rocked' we move on to the next. We also "tap" the side of a tube once the socket is quieted down just to be sure there are no structure issues inside that tube. A tube (in a clean socket) that goes "crackle" when tapped on the side has a problem and will prevent the receiver from being stable. The two tiny metal 'Nuvistor' tubes V1 and V2 can be stubborn about quieting down and might require repeated application of the cleaner. But any kind of shift or drift in the behavior of all the radio's circuits can have an effect on the S-meter. 73 You are amazing as always sir! I followed your instructions and it certainly made a difference on the S-meter performance!! I will see later today if the zero out part is ok. I did order a new S-Meter pot from Barkett just in case. thank you sir! Oh and that power supply brd for my JB 2000 ( 10/80) is amazing as well !!
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Post by husker on Aug 1, 2019 18:48:08 GMT -5
Good afternoon all, I have gotten (with help from all of you!!) my latest MrkIII working amazingly well! Except I do have a question about the S-meter. Seems it will not stay set when you zero it and doesnt seem to move very well with ambient noise. With a decent signal, the meter shows it well, but..
Every single time I zero the S-meter, it just seems to not hold that at all. I have asked a friend of mine and he said his MrkIII is the same way and my other Mrk III does the exact same thing. Is it just waht it is..or is there an isssue I can correct??
Many thanks
Bob
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Post by husker on Jul 5, 2019 1:45:10 GMT -5
Spent the evening (after everryone went to bed) trouble shooting. Seems someone cranked the mic gain pot all the way up. Turned it down to a good level and away we go!!!!! WOOHOOO, radio is working perfect!!!!
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Post by husker on Jul 4, 2019 10:25:23 GMT -5
It appears my MarkIII has a failed mode switch. The transmit meter Tends to get pegged in the mod mode when I key. But in SSB I can set the bias fine... strange
But how would I by-pass the mode switch ? Can I do this And not have to replace it?
Anyone know the cost to ya e someone replace it? I know the Part alone is $80 bucks.
Thanks guys!
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Post by husker on Jul 3, 2019 23:07:21 GMT -5
And she is alive and kicking! Thanks Chris and Dave!!
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Post by husker on Jul 2, 2019 15:18:49 GMT -5
Thanks guys, after I sat for a bit I hit me there are only three sections wired. I also have a wirewound resistor to replace the R60 with. I listen to what that Nomad guy says
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Post by husker on Jul 2, 2019 12:17:51 GMT -5
Any ideas how to change this back to a 3 section from the 4 section it's wired for?
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Post by husker on Jun 29, 2019 2:23:03 GMT -5
Interesting, I wonder just how many variants of the MrkIII there are?
Thanks Chris for your help and you as well Dave!
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Post by husker on Jun 27, 2019 21:59:03 GMT -5
Even with the 1k sandbar removed, I am still getting 8 watts dead key... very strange Check the screen grid resistor R23. Should be 15K. I have a 35k 2 watt in r23 Attachment Deleted
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Post by husker on Jun 27, 2019 15:48:04 GMT -5
Any thoughts on why someone would put a 1uf 50v cap in that spot I circled?
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Post by husker on Jun 27, 2019 13:44:05 GMT -5
Even with the 1k sandbar removed, I am still getting 8 watts dead key... very strange
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Post by husker on Jun 26, 2019 22:22:09 GMT -5
Can't see any markings on the small resistor, but it's clearly in parallel with R49. Odds are its resistance value is a lot lower than 2000 ohms. It doesn't belong there. Removing it should bring the carrier back down to a safe level. 73 any thoughts on why they added a 1uf 50 cap here?
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Post by husker on Jun 26, 2019 22:17:03 GMT -5
it is a 1k, and it is gone. One problem at a time lol.thanks!
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Post by husker on Jun 26, 2019 21:43:24 GMT -5
What you're looking for is R49, normally a 10-Watt wirewound part. This pic shows the area just under the short 2-section "can" filter cap. 73 the small one sandbar 1k..this one Chris? Attachment Deleted
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Post by husker on Jun 26, 2019 16:06:47 GMT -5
So I should look for a jumper if you will right there. Interesting and thank you!
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Post by husker on Jun 26, 2019 8:20:06 GMT -5
Sorry for bringing up this old thread, but I just acquired another mrkiii with the same issue. Still learning my way around the Browning side, would it be possible for someone to point me to where I should look for the strapped resistor? Right now I am keying 11.5 watts. The radio has all original Browning tubes EXCEPT for the final and now I see why thanks in advance
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Post by husker on Feb 4, 2019 23:02:10 GMT -5
Mine did that the other day. It ended up being the V3/ 12at7 tube. Tube was good, but the pins & socket needed cleaning. When i did that the receive came back. 238 Well, I tried what you said...son of a gun if AM didnt come back! Now on the SSB lol
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Post by husker on Feb 4, 2019 22:45:31 GMT -5
I am thinking part of the relay is stuck. The 8.5 K sandbar gets so dang hot, it would blister your finger. zthat's nt good lol
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Post by husker on Feb 4, 2019 0:38:47 GMT -5
Hi all, I have been working on my Mark III for over a decade slowly doing work between other projects. I had the AM working awesome, but no SSB receive at all. I went to adjust the plate tuning, the screw was frozen, when it let go it moved way to much and pegged my swr/power meter. I re adjusted it but now I have no receive at all even in AM. SPOT doesn't work either (it did). So it seems the relay isnt fully resetting? Also the 8.5k sandbar resistor is getting extremely hot in the transmitter side.
There is a slight hiss (like static) but no receive. On the SSB side, it isn't working either. I can transmit but zero receive at all. No hiss no nothing. I have replaced all the caps, any burnt resistors etc.
HELP guys..I want my MarkIII to work!!!
Bob
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Post by husker on Feb 20, 2018 1:47:14 GMT -5
Here's the first one. Just need to replace the receive lamp The second is in pieces to be worked on
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Post by husker on Feb 19, 2018 1:32:38 GMT -5
So a local had two Cobra 2000's, no speakers or Mics and both looked a bit rough. I traded him a Working ok kenwood TS820S for both 2000's and he added a few bucks extra Got home, opened the radios up and to both mine and his surprise the radios are in very good shape! The worst looking on was beautiful inside and the older Taiwan one looked great for its age. I am happy.. anyone have an extra Speaker for the Cobra they want to sell and yes Sandbagger...it has become a collection lol
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Post by husker on Feb 19, 2018 1:27:36 GMT -5
no...it is now a donor parts box at this point. There's a reason for this
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Post by husker on Feb 17, 2018 13:16:33 GMT -5
Does this sound like a stuck meter? Of could it be something else?
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