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Post by Night Ranger on Jun 7, 2012 5:49:19 GMT -5
I listened in to the C.R.R. last night over the live feed. I had the radio on as well, but the propagation between South Carolina and P.A. was too long. I could hear upstate New York and Canada, but I never heard Pennsylvania. I had my camera aimed at the radio too, so you could see your signals coming in to South Carolina. Oh well. Better luck next time.
Night Ranger
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Sandbagger
Administrator/The Boss 
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Post by Sandbagger on Jun 7, 2012 6:22:23 GMT -5
I listened in to the C.R.R. last night over the live feed. I had the radio on as well, but the propagation between South Carolina and P.A. was too long. I could hear upstate New York and Canada, but I never heard Pennsylvania. I had my camera aimed at the radio too, so you could see your signals coming in to South Carolina. Oh well. Better luck next time. Night Ranger The skip last night seemed to be mostly F-layer derived, as it started fading about a half hour after the sun went down. I was late coming to the show due to softball. I had originally intended to fire up the Browning, but in the name of expediency, I chose the easier to connect to SBE Console II. But the summer will be a long one, and there will be plenty of E-Layer DX opportunities. |
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Post by spitfire441 on Jun 7, 2012 6:38:19 GMT -5
I listened in to the C.R.R. last night over the live feed. I had the radio on as well, but the propagation between South Carolina and P.A. was too long. I could hear upstate New York and Canada, but I never heard Pennsylvania. I had my camera aimed at the radio too, so you could see your signals coming in to South Carolina. Oh well. Better luck next time. Night Ranger The skip last night seemed to be mostly F-layer derived, as it started fading about a half hour after the sun went down. I was late coming to the show due to softball. I had originally intended to fire up the Browning, but in the name of expediency, I chose the easier to connect to SBE Console II. But the summer will be a long one, and there will be plenty of E-Layer DX opportunities. It was very much noisy to start, I agree with 'Bagger, there was some solar activity lately so most likely F layer. I was using my first time on air, B&W 5100B high level plate modulated boat anchor. Things were going well for a first run. I had some hum in my audio but that may be due to my temporary mic connection. I tried to boost the audio level but wound up with too much bias on the modulator tubes and off she went(into oscillation). I only wound up shorting out a rectifier tube. I have some more restoration work on this transmitter, but the potential for a first rate AM transmitter is there. |
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Post by spitfire441 on Jun 7, 2012 8:52:38 GMT -5
...Well after replaceing the rectifer tube, 5R4, the radio is back up and running.
With one notable exception, if I try to get above about 60% modulation the thing wants to go into audio oscillation, or the pig wants to Hatfield,lol.
Any ideas?
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Jun 7, 2012 8:57:04 GMT -5
...Well after replaceing the rectifer tube, 5R4, the radio is back up and running. With one notable exception, if I try to get above about 60% modulation the thing wants to go into audio oscillation, or the pig wants to Hatfield,lol. Any ideas? Start with a solid mic connection, then check your audio chain. It seemed a bit off to me last night that you had to run an amplified mic up all the way to sound decent. That radio should have plenty of audio with an unamplied Hi-Z mic. You might have some resistors that have changed value... |
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Post by cbrown on Jun 8, 2012 9:01:45 GMT -5
Could be a weak audio tube, too.
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Post by spitfire441 on Jun 8, 2012 9:15:46 GMT -5
Well I've got the B&W torn apart. It is not a tube issue as all the tubes were tested or replaced. It is not my filiment dropping resistor for the audio driver tube. All resistors in the audio chain are in tolerance. It is recomended to replace all the .001 cap w/ .1 cap in the audio chain, but I dont think that is the issue here.
I went trough the power supply and I found the selenium rectifier for the 6146's bias supply, may be bad. Also to me it does not look wired the same as the schematic, it has ben solderd on BADLY by someone before.
Both bias supply pot's are jumpy on the ohm meter, so those are getting chucked.
I wish I could just find a smoking gun, but not to be. Keep you updated to progress.
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Post by "Doc"Hammer on Jun 8, 2012 9:36:10 GMT -5
I'm hoping to hear this fine unit on the air sometime soon..good luck in tracking down the issue.
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Post by spitfire441 on Jun 8, 2012 9:44:54 GMT -5
Well it does work, just not right. Same as restoring any classic, car,boat, clocl or radio. Its going to take some time and TLC here. It will be worth it in the end. The modulator and final section. As well as my rack for it all. The RX'er pictured here too.   Chassis underside, mostly power supply components as each major area of the radio is in its own module  Modulator w/o tubes underside.  Chasis   |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jun 8, 2012 9:58:04 GMT -5
Well I've got the B&W torn apart. It is not a tube issue as all the tubes were tested or replaced. It is not my filiment dropping resistor for the audio driver tube. All resistors in the audio chain are in tolerance. It is recomended to replace all the .001 cap w/ .1 cap in the audio chain, but I dont think that is the issue here. I went trough the power supply and I found the selenium rectifier for the 6146's bias supply, may be bad. Also to me it does not look wired the same as the schematic, it has ben solderd on BADLY by someone before. Both bias supply pot's are jumpy on the ohm meter, so those are getting chucked. I wish I could just find a smoking gun, but not to be. Keep you updated to progress. You can replace a selenium rectifier with a modern diode. Just make sure you install one with the proper PIV and current ratings, and measure the DC voltage and adjust biases as needed. |
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Post by spitfire441 on Jun 8, 2012 18:43:55 GMT -5
Well I've got the B&W torn apart. It is not a tube issue as all the tubes were tested or replaced. It is not my filiment dropping resistor for the audio driver tube. All resistors in the audio chain are in tolerance. It is recomended to replace all the .001 cap w/ .1 cap in the audio chain, but I dont think that is the issue here. I went trough the power supply and I found the selenium rectifier for the 6146's bias supply, may be bad. Also to me it does not look wired the same as the schematic, it has ben solderd on BADLY by someone before. Both bias supply pot's are jumpy on the ohm meter, so those are getting chucked. I wish I could just find a smoking gun, but not to be. Keep you updated to progress. You can replace a selenium rectifier with a modern diode. Just make sure you install one with the proper PIV and current ratings, and measure the DC voltage and adjust biases as needed. The parts list only mentions , 64ma, the line in about -150volts. So just rate it according to that? |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jun 8, 2012 20:55:45 GMT -5
You can replace a selenium rectifier with a modern diode. Just make sure you install one with the proper PIV and current ratings, and measure the DC voltage and adjust biases as needed. The parts list only mentions , 64ma, the line in about -150volts. So just rate it according to that? Yea, I'd just opt for overkill and get a 400V PIV @ 1A. They're cheap enough, and Radio Shack still carries them....(I think). |
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Post by spitfire441 on Jun 9, 2012 23:26:15 GMT -5
The parts list only mentions , 64ma, the line in about -150volts. So just rate it according to that? Yea, I'd just opt for overkill and get a 400V PIV @ 1A. They're cheap enough, and Radio Shack still carries them....(I think). ...All I needed to know. Have one in the junque box. |
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