: RCA Orthophonic Console SHF-5 need help  ( 1885 )

TC Chris

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RCA Orthophonic Console SHF-5 need help
« #15 : April 11, 2021, 04:56:56 PM »
On V2, a 6CG7, hum on pin 7 but not 2 suggests maybe the coupling capacitor C15 is bad.  How about on V1, also a 6CG7?  If you have noting on pin 2 of V2 then you should also get nothing from either in of V1.

Chris Campbell


thermofin

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RCA Orthophonic Console SHF-5 need help
« #16 : April 19, 2021, 07:34:28 AM »
I only checked pins 2 and 7 on V1 not V2. I will do that this afternoon. I replaced C15 and I usually check the old and new caps but could have missed this one. I'll check it again as well.

Thanks

thermofin

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RCA Orthophonic Console SHF-5 need help
« #17 : April 26, 2021, 04:35:45 PM »
I'm still struggling with this unit. I was not confident with the supplier of the 6CG7 tubes so I ordered another pair to eliminate those from the equation. The 3 pair I have are all operating similarly so I am confident the tubes are not an issue. I have touched the 2 and 7 pins on both V1 and V2 and I only get a hum on pin 7 of V1. Nothing on the other pins.
On another note, I am getting low volume sound (that is adjustable) with the volume knob is turned all the way up and the changer plugged in to the TAPE jack. This occurs when the dial is set to either TUNER or PHONO. No sound when the DIAL is set to TAPE.
I still have non-adjustable (~half) sound when plugged into STEREO and dial set to STEREO.
Help please!

TC Chris

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RCA Orthophonic Console SHF-5 need help
« #18 : April 28, 2021, 08:59:31 PM »
Are you sure you have counted properly? Here's a guide to pin numbering, viewed from the bottom (i.e., under the chassis):

http://www.dogstar.dantimax.dk/tubestuf/pinout.htm

Pins 2 and 7 are both grids, the signal inputs to the tube.  Start at pin 2 of V2, then pin 7 of V1, then pin 2 of V1.

As to the "tape" input, is this the input from a tape deck, or the output to it for recording purposes?  On my '56 Maggie, it was a bit hard to figure out which was in and which was out--lousy labeling.

Chris Campbell

thermofin

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RCA Orthophonic Console SHF-5 need help
« #19 : May 04, 2021, 01:04:37 PM »
Thanks for the response.
I reviewed the pin instructions and I am on the correct  pin #'s. Just to be sure of the procedure, I should have the dial set to "phono" and touch these pins with a screwdriver. How noticeable should the hum or clicking be? Pin 7 on V1 makes a very noticeable hum when touched but I  I don't seem to hear anything on the others. Should the volume be turned to high?
The RCA jacks are all 4 on one side of the amp. Phono and Tuner, Tape and Stereo. I'm fairly sure these are inputs. The manual shows connecting a stereo tape unit to both TAPE and STEREO to get the stereo output.
I'm not sure why I'm getting low sound with the dial setting on TUNER or PHONO when the changer is plugged into "TAPE".
I'm out of town but will be back on the 10th and will check pins again. If there is anything else you can think of that I can do to troubleshoot, please advise. If there are any potentially obvious components that need to be checked let me know.
Thanks.