Re: L7 REPAIRED
Jim
I have two L7, one bonded grids and other stock.? The bonded grids makes more power than stock.? It is the stock one I need to have OK as it is sold waiting to be picked up.? I just want it
By
Paul Kraemer
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#76848
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Re: R4B AVC issue
Yep, I do agree, I'll dig into the schematic once more ;)..
[email protected]> wrote:
By
Michael Jensen
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#76847
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Re: R4B AVC issue
That is almost perfect. It has to be in the bridge circuit or the meter itself.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from [Proton
By
Steve Wedge, W1ES/4
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#76846
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Re: L7 REPAIRED
Paul, I assume you have the grids directly bonded to the chassis ?? ? That alone will improve stability.? I would leave the suppressors alone.
Do you have a hi-pot tester ?? ?One / both tubes
By
Jim VE7RF
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#76845
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Re: R-4C Frying Egg/Static Noise
Rob, Bob, and Michael,
Thanks for your suggestions.? Looks like the problem noisy tube was V5 (6BA6) Last IF Amp tube. I had a spare on hand so I should be good for now. I had not had the covers off
By
Ed G
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#76844
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Re: R4B AVC issue
We are at -1.345 at TP2 detuned and no antenna connected.
After swapping V4&V5 I did no adjustment to the circuit.
[email protected]> wrote:
By
Michael Jensen
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#76843
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Re: Another TR7 Journey begins
I found an eBay photo that shows C1029 as a NP0 temperature coefficient. That's what you will want to use if possible for any added cap.
73
-Jim
NU0C
"Jim Shorney via groups.io"
By
Jim Shorney
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#76842
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Re: Another TR7 Journey begins
In that case C1029 is your target. These radios are over 40 years old. If the crystal was on the edge of tolerance to start with it would not surprise me if it has aged out just enough to make
By
Jim Shorney
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#76841
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Re: L7 REPAIRED
Where did you see the faint orange glow? If it was in the tube (not on the plate) then the tube has leaked, but surprised it did not just flash over and pop the fuse (and possibly the grid
By
Gary Follett
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#76840
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Re: L7 REPAIRED
Please enlighten me Gary.? With the imports installed the tune and load just didn't "feel" right and it was interesting to me that there was a faint orange glow for nominal power output(same in both
By
Paul Kraemer
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#76839
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Re: L7 REPAIRED
Well, aside from marginal vacuum, the RF Parts tubes are good. They just have more gain than the originals, and this makes them more susceptible to instability.
There are parasitic choke upgrades
By
Gary Follett
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#76838
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L7 REPAIRED
The L7 I recently had instability problems and tune capacitor arc has been REPAIRED.? I managed with time and a jeweler file to clean the burn from the capacitor plate without removing it.? I
By
Paul Kraemer
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#76837
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Re: T4XC/R4C
I have some general coverage crystals, but no WARC. Rob, NC0B
By
Rob Sherwood
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#76836
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Re: T4XC/R4C
Also, you can buy new xtals from AF4K:
https://yhst-172765969-1.store.turbify.net/drake-4line-crystal--hc49-hol449.html
--lyndon
By
Lyndon VE7TFX <lyndon@...>
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#76835
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Re: T4XC/R4C
Ken KG8FM writes:
Lots of crystals on eBay -- search 'drake crystals'. There's a
good selection covering the SW broadcast bands, but WARC band
crystals have been pretty scarce of late.
--lyndon
By
Lyndon VE7TFX <lyndon@...>
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#76834
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Re: Wanted an Original manual for the RV-75
I am still on the lookout for an original of the RV-75 manual. The one with the foldout schematics in the back. I am good on QRZ for info. Thanks in advance. Original only not a copy
73? Bob
By
K6OXN Bob
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#76833
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Re: T4XC/R4C
I have some extra xtals. What bands are you looking for?
Skop
By
Skip
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#76832
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Re: T4XC/R4C
I have had good luck and have gotten quality/tested stuff from: https://ke9pq.com/ Enjoy the C-Line I have a set and use and enjoy often!
KF0KZP
By
Mark KF0KZP
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#76831
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T4XC/R4C
Hi all,
Just picked up the Drake C-Line and would like to pick up crystals for
general coverage and WARC bands who do I get them from?
Any help would be appreciated!
KG8FM
Ken
By
Ken KG8FM
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#76830
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Re: Another TR7 Journey begins
I can¡¯t find any specs on the Tenma 72-460. Tenma makes decent equipment, but the 72-460 may not be as sensitive as laboratory grade instruments from a variety of manufacturers, including HP.
By
Omni
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#76829
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