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(03-12-2015, 10:57 AM)PAradiogeek Wrote: Kirk,
I don't know how to sort this bad boy out. Looking at the Model 979 schematic, there are differences. On the good side, that schematic shows 2 caps (both 20 uF), but there are tube line-up differences. The converter is a 6K8 (instead of a 6A7), the IF is a 6K6 (instead of 6D6), the rectifier is a 25Z6 (instead of a 25Z5), and the ballast is a BM43B instead of a BM49C.
According to my tube substitution data, the 6K8 and 6A7 are not subs for one another. The 6K6 and the 6D6 are similar though not direct substitutes. The rectifier tubes seem to be direct replacements.
I don't believe that the ballast tube difference is very significant (maybe someone down the line swapped a '49C for the original '43B).
In any event, if you want to go with that schematic, both caps are shown as 20 uF caps, but I honestly don't think the Model 979 is the right model to use. Too many differences.
A 6K8 is a mixer-oscillator/converter tube though, but a triode-hexode rather then a pentagrid type, they could use the 6K8 with some electrical changes, other then the fact the 6K8 uses an octal socket of course. A 6k6 is definitely NOT a substitute for a 6D6, a 6K6 is a power output tube, basically an octal based version of a type #41. I believe you may have been thinking of a 6K7 rather then a 6K6, either that or there was a misprint in your tube substitution manual where they meant to print 6K7 or 6K7G, a type #78 tube is a substitute for a 6D6. A 25Z6 was the octal based successor to a 25Z5, actually it's a more robust tube then a 25Z5, both were intended to be used in a voltage doubler power supply circuit though 99 out of 100 radio models that used them had the two diodes wired in parallel.
Regards
Arran
Posts: 496
Threads: 15
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City: Weymouth Ma
Kirk,
This is a tough one for sure! I have not looked at the schematics yet but the manual I looked at shows a whole different tube line up for the model 911 including using a 6x5 rectifier.That manual is the one that shows the 6g5 being used in the model 979 which is why I did not look at the schematic for that one. I have found no reference to a model 919 in any manual yet. Could it be that it was marketed under under name?
Henry
Posts: 4,108
Threads: 310
Joined: Nov 2013
City: Kings Park NY
No idea Henry,
It was definitely sold under Automatic or Maybe hazeltine as it says on the tag. A few of my mystery Halsons have the same issue.
Still havent made it to the house to get the wiring details.
Dont kill yourself doing this. Mike is gonna fix it.
I'm sure it is something small because it was working for a few minutesn then later when i turned it on it didn't get any stations.
UGH
Kirk
Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
Posts: 15,704
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
If you are in no hurry, I will fix it for ya but right now I have to:
1. Move
2. Do my taxes
3. Set up shop in the new place.
How fast do you need this?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 4,108
Threads: 310
Joined: Nov 2013
City: Kings Park NY
I can wait 2 years Mike, No rush at all!
Not like you gave me any cabinets when I was moving...........................................
Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
Posts: 496
Threads: 15
Joined: Mar 2013
City: Weymouth Ma
Kirk,
I'm sure it is a quick fix for someone with a little more experience. Mike will have no problems . I am interested in finding the documentation that's all.
Good Luck,
Henry
Posts: 15,704
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
I gave you the cabinets while you were still in renovation mode
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 03-14-2015, 02:20 PM by morzh.)
Posts: 4,108
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City: Kings Park NY
I should have buried them in the walls.
The ?? what the hockey stix model is that.. Anyway I think it will need a loooooooooot of TLC.
I saw it today on top of a stack of furniture, wish I hadnt
Kirk
Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
Posts: 15,704
Threads: 551
Joined: Oct 2011
City: Jackson, NJ
I am seriously mulling over buying a pet rat.... . A piece of Jarlsberg inside that yammie looking well waxed coil will be a housewarming gift
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 03-14-2015, 05:44 PM by morzh.)
Posts: 4,108
Threads: 310
Joined: Nov 2013
City: Kings Park NY
His name will be Misha and he will only eat crappy cabinets that are broken in shipping. As you would say... Muahahahaha
Kirk
Times I have been electrocuted in 2021
As of 1/01/2021
AC: 4 DC: 1
Last year: 6
(This post was last modified: 03-14-2015, 08:06 PM by OldRestorer.)
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