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Zenith 7H920 AM/FM set 7 tube
#59

10 15 am- extracted chassis and ran the set which in all respect seems its working fine yet im in the garage and the ambient room temp is 55deg,,,, wood heat is fixing that issue.
11 15 am- still not failing
12pm - added heat gun air to top and bottom about 12'' away for about 5min ,  still no fail

12 01 pm - i use a non-conductive screw driver and start poking at all the parts and wires underneath attempting to check for intermittent connections,, none of my prodding produces any bad noises out of the speaker.

12 30 pm - still no fail.
12 45 pm - put radio back inside the case to let it build up heat  on its own kinda trapping it like normal

1 30pm - still not failing

1 45 pm - i check the operation of the outlet in the house i am using,, it passes,, radio still not failing

2pm - i phone  a friend... update him on the radio... we have no clues other than dont bring the radio in the house. the idea is to set the radio on the porch, open a window and let the wife enjoy it since she's taken ownership of it as soon as she saw it. ,, LOL (winter time). The radio is still not failing

2 15 pm - i give up and start putting my knobs on and chassis to cabinet bolting hardware all while the radio is still playing.

2 17 pm - i get to the third chassis mounting screw and the set starts to fail

i observe whats happening as the screw is tightened down,,,,, the Bakelite cabinet iitself is not level along the bottom where the chassis sits,  its slightly warped or tweaked,, and thus as i tighten down my bolts, the chassis "twists" so to speak.

i back off on all my chassis to cabinet hold down hardware and the noise starts to dissipate and go away and the station i am on becomes clear again.

so.... on the cardboard back i put a piece of tape on there and wrote this :

"Finger tighten *only* the chassis to cabinet hardware on the bottom or the radio will start to crackle and pop.  suspect a cold solder joint or cracked tube socket somewhere"

this will be my fix to the problem because the last thing i want to be doing is chasing down something that is probably microscopic especially with the set is playing just fine now.

so..... another odd ball problem i encounter.


Messages In This Thread
Zenith 7H920 AM/FM set 7 tube - by jcassity - 11-30-2018, 03:04 PM
RE: Zenith 7H020 AM/FM set 7 tube - by jcassity - 11-30-2018, 03:11 PM
RE: Zenith 7H020 AM/FM set 7 tube - by jcassity - 11-30-2018, 03:12 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 11-30-2018, 07:41 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 11-30-2018, 07:51 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-01-2018, 01:01 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-01-2018, 08:55 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-01-2018, 09:22 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 10:32 AM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 11:58 AM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-02-2018, 12:31 PM
RE: Zenith 7H920 AM/FM set 7 tube - by KCMike - 12-02-2018, 01:17 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 01:45 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 02:46 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 04:45 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-02-2018, 08:24 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 09:00 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-02-2018, 09:02 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-02-2018, 10:10 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-03-2018, 11:33 AM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-03-2018, 08:26 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-03-2018, 10:10 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-04-2018, 09:08 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-04-2018, 09:33 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-04-2018, 10:18 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-05-2018, 10:27 AM
RE: Zenith 7H920 AM/FM set 7 tube - by EdHolland - 12-05-2018, 02:30 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-05-2018, 05:22 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-05-2018, 08:41 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-05-2018, 10:53 PM
RE: Zenith 7H920 AM/FM set 7 tube - by Arran - 12-07-2018, 03:08 AM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-07-2018, 09:29 AM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-07-2018, 02:04 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-07-2018, 10:06 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-08-2018, 09:27 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-09-2018, 11:59 AM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-09-2018, 12:02 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-14-2018, 10:27 AM
RE: Zenith 7H920 AM/FM set 7 tube - by EdHolland - 12-14-2018, 02:41 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-14-2018, 04:27 PM
RE: Zenith 7H920 AM/FM set 7 tube - by LarryFS - 12-14-2018, 05:51 PM
RE: Zenith 7H920 AM/FM set 7 tube - by TV MAN - 12-15-2018, 11:48 AM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-15-2018, 02:16 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-17-2018, 08:13 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-18-2018, 08:25 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-18-2018, 10:01 PM
RE: Zenith 7H920 AM/FM set 7 tube - by David - 12-18-2018, 10:41 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-19-2018, 10:15 AM
RE: Zenith 7H920 AM/FM set 7 tube - by Ed Locker - 12-19-2018, 10:54 AM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-19-2018, 12:10 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-19-2018, 12:11 PM
RE: Zenith 7H920 AM/FM set 7 tube - by Ed Locker - 12-19-2018, 03:19 PM
RE: Zenith 7H920 AM/FM set 7 tube - by jcassity - 12-19-2018, 08:13 PM



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