Re: Puzzling problem with the AGC in my R4-C
Also here: https://www.youtube.com/watch?v=D0drh4V-cL4 Jim W7RY -- Thanks and 73, Jim W7RY
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Jim W7RY <jimw7ry@...>
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#69899
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Re: Puzzling problem with the AGC in my R4-C
They are non polarized and more reliable than an electrolytic. See here: https://www.youtube.com/watch?v=67M7fsbLUIU 73, Jim W7RY -- Thanks and 73, Jim W7RY
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Jim W7RY <jimw7ry@...>
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#69898
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Re: TR7 Service Kit - Extender Boards Needed
Thanks Gary, I did notice that those switches are a bit "dirty".? I haven't put the rig on the bench yet. just getting prepared with everything I might need to give it a thorough restore to full
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John B
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#69897
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Re: Puzzling problem with the AGC in my R4-C
Gary, The S meter is behaving as you described with a steady signal. The only issue that has me puzzled is how the audio distortion increases as the AGC time constant is reduced. I haven't seen this
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Bill Leonard N0CU
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#69896
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Re: Puzzling problem with the AGC in my R4-C
?S=Slow AGC response time M=Medium AGC response time F=Fast AGC response time Fast is only really suitable for use in CW and RTTY. SSB will get quite distorted in the Fast AGC position and less so
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Gary Follett
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#69895
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Re: Puzzling problem with the AGC in my R4-C
Thanks Jim. I'll get them on order from Mouser. I am curious what performance feature about these capacitors requires their use in the AGC circuit. -- Bill N0CU
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Bill Leonard N0CU
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#69894
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Re: Puzzling problem with the AGC in my R4-C
I recommend these in the proper values: https://www.mouser.com/ProductDetail/598-473MPW630K Please don't order some chinese junk from amazon or ebay. Use these from Mouser or Digikey. 73, Jim W7RY --
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Jim W7RY <jimw7ry@...>
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#69893
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Re: Puzzling problem with the AGC in my R4-C
They are the two large caps on the AGC board. They are the size of small electrolytic capacitors, but they are not polarized, so I don't know what type they are: C73: 0.22 uF C74: 0.047 uF -- Bill
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Bill Leonard N0CU
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#69892
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Re: Puzzling problem with the AGC in my R4-C
Any capacitor (especially an old one, even more so where it's in a very hot environment all its life) can easily go bad. What are the values of the capacitors? 73, Jim W7RY
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Jim W7RY <jimw7ry@...>
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#69891
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Re: TR7 Service Kit - Extender Boards Needed
Clean the push buttons for ¡°Fixed XMIT¡± before you go in to extensive troubleshooting. Best to clean the ¡°FIXED RCVR button and the ¡°AUX Program¡± rotary switch as well. I think this will fix
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Gary Follett
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#69890
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TR7 Service Kit - Extender Boards Needed
I have a TR7 that I picked up at a local hamfest, it came with the matching power supply.? I've gone through the power supply, cleaned it up and tested it.? All is good there.? The TR7 receives but
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John B
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#69889
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Puzzling problem with the AGC in my R4-C
The receiver seems to work fine when the AGC switch is set to S. However, in the M position there is noticeable distortion on both noise and signals. In the F position, the distortion becomes
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Bill Leonard N0CU
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#69888
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Re: T4XC help
Yes, now that I have gone through this, testing of the shunt resistor on an unknown T4 should be one of the first things you do even before you apply power. It should definitely be replaced with a
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Doug Crompton WA3DSP
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#69887
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Re: Cinch Jones connector identification
Thanks, Jim. Yes, I am aware the RV75 will work without the RIT cable but curiosity has the best of me and it appears to be an easy task. Rick K8EZB
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Rick K8EZB
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#69886
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Re: Cinch Jones connector identification
Jones plug nomenclature on the web suggests P-3312-CCT. However, you only need this if you actually want to use RIT. The RV75 works just fine without it an honestly I have never missed it because I
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Jim Shorney
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#69885
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Cinch Jones connector identification
I recently acquired an RV75 to use in my 7-line station. The RV75 requires a cable from the RIT SWITCH phono connector on the rear panel to the ACCESSORIES connector on the rear panel of the TR7. This
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Rick K8EZB
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#69884
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Re: DIN connectors
The Metal Body circular DIN connectors exist, BUT typical hobbyist & radio amateur will *Constantly Complain about PRICE*. These two (2) manufacturers are found through ALL Major Electronics
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Greg W9GB
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#69883
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Edited
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Re: T4XC help
Doug: Two resistors I ALWAYS check on a new-to-me T-4XC - R49 and R59 on the T/R relay board. One of those is the 3.3 Ohm shunt resistor and the other is in the +250V supply line. Both are easy to
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VE7PS
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#69882
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Re: T4XC help
This is NOT a bias issue - read my original message. If anything, the bias is set too low due to an elevated shunt resistor value or opened shunt resistor. I am fairly confident that is the problem
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Doug Crompton WA3DSP
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#69881
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Re: T4XC help
If the plate current is pegged, it is way too much. It is also a good way to go thru your supply of 6JB6 tubes. You need to pull out the book and set the bias. It is the best ally to save the tubes.
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David
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#69880
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