Re: RV75 Issues: Part 5
Interesting footnote: Another RV75 listed in an eBay acution closing later tonight. Said to be working and in excellent condition. Bidding at $245 as of 9 AM ET. I would not be surprised to see this
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Rick K8EZB
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#76351
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Looking for an MS-4 in EU
Dear group, I am looking for an MS-4'(speaker only) for a reasonable price to complete my second set of 4C-Twins.? As shipping and import taxes to the EU have become ridiculously high lately, I am
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Rob PA9Z
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#76350
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Re: RV75 Issues: Part 5
"Rick K8EZB" <frboswell@...> wrote: Of course not. They call it shotgun repair for a reason. Find a component tester and start testing components. I have a couple of the cheap Chinese gadgets
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Jim Shorney
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#76349
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Re: RV75 Issues: Part 5
Q206 (VCXO) replaced but no joy. All measured voltages and resistances remain as before. Current status: - All voltage test points per manual within published specs - The RF output is somewhat close
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Rick K8EZB
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#76348
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Re: Drake 2B crystal calibrator
The Schematic Diagram of the Drake 2-AC Crystal Calibrator can be found in the back pages of the Drake 2-B Communications Receiver.
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Greg W9GB
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#76347
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Edited
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DRAKE 7.238 TECHNICAL NET ( February 25, 2024 )
Today we had 34 check-ins on the net. The following radio's were used. Twins = 10 TR3 = 1 TR4(x) = 14 TR5 = 2 TR7 = 3 Next week Bill, W9MXQ will be the net control. 73's, Mark, WB0IQK
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M Gilger
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#76346
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Re: Drake 2B crystal calibrator
I think I have one disassembled in a box. If I can find that, I'll get a picture of both sides of the PCB. 73, Barry - N4BUQ
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n4buq
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#76345
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Re: Drake 2B crystal calibrator
Don't know if this is what you are looking for, but here's a couple of pics. 73 Stan KM4HQE
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Stan Gammons
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#76344
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Re: RV75 digital schematic updated
And again with my typo fixed. I proofread it, honest! "Jim Shorney via groups.io" <jimNU0C@...> wrote: -- 73 -Jim NU0C
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Jim Shorney
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#76343
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RV75 digital schematic updated
I've updated K4JNG's digital board schematic image with the in circuit test points flagged and the optical interrupter part number added. -- 73 -Jim NU0C
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Jim Shorney
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#76342
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Re: RV-75 only decrements
That's good price. There are two on eBay for $11 and $15. I may have to buy a pair for spares. Thanks for the info. 73 -Jim NU0C "K6OXN Bob" <bobk6oxn@...> wrote:
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Jim Shorney
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#76341
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Re: RV-75 only decrements
OK, good. That is pointing to the optical interrupter. It may have been useful to report the actual minimum and maximum voltages coming out of the interrupter since this is essentially a analog to
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Jim Shorney
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#76340
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Drake 2B crystal calibrator
Hi all, I am currently trying to rebuild a 2AC crystal calibrator that has been butchered by a previous owner. I have stripped it down to the bare circuit board, and would appreciate a picture of the
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Brian Tibbert
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#76339
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Re: RV-75 only decrements
I also forgot to tell everyone that Green Brook Electronics is the source of the Optical Interrupters for the RV-75.? Part # is OPB813S which are $5 each shipping is $7.99 73? Bob
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K6OXN Bob
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#76338
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Re: RV-75 only decrements
I did follow the schematic, and I apologize for not reporting the voltage readings. TP101 reads 1.112 vdc and TP102 reads 8.31 vdc. TP101 does not vary when turning the tune dial, but TP102 varies
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K6OXN Bob
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#76337
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Re: RV-75 only decrements
If you want to help please look at the schematic. 73 -Jim NU0C "Clint VE3CMQ" <ve6cmm@...> wrote:
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Jim Shorney
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#76336
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Re: RV-75 only decrements
Did you make any of the voltage measurements that I asked for? Voltages on pins 2 and 7 of P102 could be helpful also. Don't assume that the part is bad just because you moved it. You could still have
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Jim Shorney
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#76335
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Re: RV-75 only decrements
Hi Bob, It sounds to me that either the emitter or detector on the one channel of the encoder isn¡¯t working. It might be easy to repair this problem. I don¡¯t have an optical encoder like the one
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Clint VE3CMQ
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#76334
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Re: RV-75 only decrements
Well by taking the Optical Interrupter apart and reversing the 2 elements, now the unit increments only. Will keep everyone informed after getting them and doing another calibration.
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K6OXN Bob
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#76333
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Re: Drake TR-7 - A repair journey
Nice Loop. I'm planning a somewhat larger one. So far, I only have the capacitor. 15-250pF @ 45kV. - Jerry, KF6VB
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jerry-KF6VB
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#76332
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