Re: TR7 - DR7 Display question
Excellent Jim, thanks very much. 73 de Raoul CE3RY
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Raoul Meunier
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#76825
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Re: TR7 - DR7 Display question
No. Pin 8 is the common ground of all the buffers if the ULN2003 chip. You can test the LED segments by BRIEFLY grounding, one at a time, pins 10 through 16 of U9032. Doing so will illuminate the
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Jim Shorney
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#76824
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Re: Another TR7 Journey begins
Just a guess, but how sensitive is your counter. The 5.645 MHz signal on Pin-40 is speced at 80mV P-P (57mV RMS) and is often quite a bit less in some TR7¡¯s. You need a counter that can read a
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Omni
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#76823
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Re: R-4C Frying Egg/Static Noise
Hi Ed, You want to start at the tail end of the R-4C. Pull the last IF tube that is a pain to remove. If the static does not go away, you know it is either the product detector or the audio amplifier.
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Rob Sherwood
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#76822
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Re: Another TR7 Journey begins
True that, but he is following the alignment instructions in the service manual which has specific requirements. 73 -Jim NU0C "Bob Loving" <bob.loving@...> wrote:
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Jim Shorney
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#76821
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Re: Another TR7 Journey begins
Did you ensure that the +10 was adjusted spot on first? You may need to play with the value of C1029 a bit. That's why it is a factory selected value, it it compensates for variations in other
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Jim Shorney
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#76820
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Re: Another TR7 Journey begins
If I remember correctly, Bill, the frequency is dependent upon the mode of operation. The frequency shifts above or below the center 5.645000-MHz frequency of the various mode filters to place the
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Bob Loving
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#76819
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Re: R-4C Frying Egg/Static Noise
A bad/leaky power supply filter cap could be the culprit, especially in the +14v line. Is it there with no antenna connected? How about with volume at zero? -- 73 de Mike, W1NR THAT was the equation.
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Michael W1NR
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#76818
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Re: R-4C Frying Egg/Static Noise
I had a noisy V4, 6BA6, IF Amplifier. Bob K9JU
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Bob Loving
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#76817
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R-4C Frying Egg/Static Noise
Folks, I have a lot of the frying egg/static noise in my R-4C. I am using the Sherwood third mixer mod so don't have the usual suspect third mixer tube.? What else could be the source of that noise?
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Ed G
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#76816
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Re: Another TR7 Journey begins
I finally had a chance to use a decent frequency counter today. The 40 MHz oscillator is now spot on 40 MHZ and the VCXO is right on 53.695 MHz.? But the 8.05 MHz oscillator still will not quite get
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Bill NZ0T
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#76815
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TR7 - DR7 Display question
Hi All, I'm trying to repair a DR7 board and I would like to "turn on" all LED segments. From the diagram, I believe that grounding pin 8 of U9032 might do it. As I don't want to ruin anything on the
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Raoul Meunier
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#76814
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Re: R4B AVC issue
Well, this is vexing, The Drake AGC circuit is very high impedance: on the order of megohms. It is employed to control the gain of the various stages by changing the bias voltage. It has been awhile,
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Steve Wedge, W1ES/4
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#76813
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Re: R4B AVC issue
Okay quick info on progress on the saga... Replaced V4&V5 with 2 NOS tubes, that brought the meter down from ~5-6 S units to ~4 S units, still the zero pot needs to be maxed/minimize depending how we
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Michael Jensen
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#76812
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Re: TR7 with low power on 15 and 10 meter
Been there. Did that. Spot on (slang for absolutely perfect). All my TR7s will get this mod. 73, -Glenn/ WB0DKT
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Glenn Hetchler WB0DKT
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#76811
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Re: TR7 with low power on 15 and 10 meter
Hi Raoul, Nice to see you are still at it. You will be better off with the version 2 predriver. 95 Watts on 15m is a good sign. If you have not seen this yet, here is a discussion of the V2 board from
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Jim Shorney
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#76810
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Re: TR7 with low power on 15 and 10 meter
Good morning Jim, It's been a long time since your last message... My apologies for taking so long to answer you; lots of home distractions here... Trying to obtain more power in 10 and 15 meters, I
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Raoul Meunier
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#76809
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Re: Soft Rubber Eqp't Feet
3M was the major US manufacturer for Adhesive Rubber Feet. 3M? Bumpon? Protective Products which featured a urethane composition with a pressure sensitive adhesive.
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Greg W9GB
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#76808
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Edited
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Re: FW: FW: [cca] wee bit off topic
If the charger is compatible with the number of cells in your battery pack(s) it *should* work. You will want to be careful of charge rates. If the batteries are not rated for fast charge you could
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Jim Shorney
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#76807
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Re: 6JB6 Tube Tester Adapter
I¡¯ll take a 6JB6 PC board Gary W0DVN
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Gary Follett
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#76806
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