Author Topic: Unknown Model  (Read 858 times)

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Unknown Model
« on: November 25, 2017, 06:06:27 PM »
Just finished bringing home the unit I had put in sightings, from Suwanee  The folks selling it helped with loading it on the truck.  It is out of order at this time.  The owner turned it on and it played the sixty cycle symphony for hammer and tongs.  It has the original back cover and it was mighty dirty and dusty inside.  it has the receiver, amp and a small module I assume to be the demultiplexer.  There is a block layout that doesn't include the smaller module.  The sliding covers appear to have had stain spilled on them and some ran down the back cover.  There isn't a model number to be found on or in it, so I am at a loss to identify it.  The owners have another console that is good looking and working, so I recommended this site to them.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

electra225

  • Hero Member
  • *****
  • Posts: 1930
    • View Profile
Re: Unknown Model
« Reply #1 on: November 25, 2017, 07:44:08 PM »
There might be a model sticker, inside, on the bottom of the cabinet somewhere.  Normally covered in a half inch of lint and dust.  It might also be on the inside of the front panel somewhere.  That would be in black ink.  Good luck.  Nice find!  I'm glad you got it.
If it ain't broke, call me.  I can break it....

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #2 on: November 26, 2017, 06:59:43 PM »
No stickers anywhere, save the incomplete layout sticker on the floor.  it appears to most closely resemble the ST 621 model from the 1962 sales brochure, though the tubes with the first chassis I have removed are dated 1-63.  It is the amp/ power supply.  I can't believe it only has 2 other capacitors other than the multisection.  It looks like someone had spilled stain on the sliders.  They are not deformed, just discolored.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #3 on: November 28, 2017, 06:58:54 AM »
Just ordered the caps to make up the multisection in the amp / PS  This is looking to be much easier than my '47.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

electra225

  • Hero Member
  • *****
  • Posts: 1930
    • View Profile
Re: Unknown Model
« Reply #4 on: November 28, 2017, 07:21:05 PM »
I wonder if yours has the weird plug on the Molex connector like my ST253 does.  I'd say the 621 is close enough, since you will use the model numbers on the various chassis for service literature in any case.  What amp and tuner does yours have?  Does yours have the RCA input connectors on the rear apron of the tuner on on the top of the tuner chassis?  1-63 is a very late production date for a tube job.  It will be a robust performer.  You'll be amazed at the sound that comes out of a fairly small instrument. Be sure to check the resistors in the amplifier.  You followed me thru my other projects, so you know the drill.  You gonna re-stuff the filter cap cans?
If it ain't broke, call me.  I can break it....

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #5 on: November 28, 2017, 10:21:48 PM »
The amp is marked 9308-10.That's as far as I have gotten into it.  As for the elyts, I will do what I did with the older unit:  Leave the original in position and install their substitutes beneath the chassis.  Everything is filthy and the amp looks like it had gotten we tand has a discolored, corroded area on top where the filth absorbed it and acted like a poultice.  The chassis interior looks good, but it ain't gonna look like a Scott.  I hope for it to sound like one.  It's good the back cover is in good physical shape.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #6 on: November 29, 2017, 08:01:18 AM »
On the end item sticker, it appears that the caps in the crossover are 16uF.  What would be the proper voltage rating?  I have found sources for these at a 100v rating.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

electra225

  • Hero Member
  • *****
  • Posts: 1930
    • View Profile
Re: Unknown Model
« Reply #7 on: November 29, 2017, 09:33:58 PM »
The crossover caps are 16uf, non-polarized, are they not?  IIRC, the ones I used were from Radio Shack.  I used two 33uf at 50 volt electrolytics and connected them negative to negative to give me non-polarized e-caps for the crossover.  If you have 100 volt units on hand, those would work fine, just be a tad overkill is all.  The originals are probably 16uf at 25 volts.


Does your 9300 amp have a 5U4 rectifier and 6BQ5 audio output tubes?  I wondered if 1962 was the last year for the 9300, but I see it wasn't.  You will LOVE that thing when you get it done.  The 9300 series amp is the absolute best Magnavox ever built.  A wad of 0000 steel wool and some Simichrome polish might help the funky finish on the amplifer chassis.  If it is not pitted, it might clean up very nicely.
If it ain't broke, call me.  I can break it....

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #8 on: November 29, 2017, 10:10:43 PM »
I saw the caps on Ebay.  I'd never seen radial leaded non polar caps before.  You are correct on the tube compliment.  I hope it does all right
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #9 on: November 29, 2017, 10:17:36 PM »
There were some green radial leaded caps I saw this morning, but I just found these:  https://www.ebay.com/itm/10pcs-100V-16uF-100V-12-5x30mm-ELNA-NP-Bipolar-Axial-Electrolytic-Capacitor/282697397094?hash=item41d213f366:g:g4UAAOSwvzRXzUEJ

They will be a wait though.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Ken Doyle

  • Jr. Member
  • **
  • Posts: 74
    • View Profile
Re: Unknown Model
« Reply #10 on: November 30, 2017, 11:26:01 AM »
A wad of 0000 steel wool and some Simichrome polish might help the funky finish on the amplifer chassis.  If it is not pitted, it might clean up very nicely.


I wouldn't use steel wool anywhere near an amplifier or radio chassis.

TC Chris

  • Hero Member
  • *****
  • Posts: 1158
    • View Profile
Re: Unknown Model
« Reply #11 on: November 30, 2017, 07:06:16 PM »
A wad of 0000 steel wool and some Simichrome polish might help the funky finish on the amplifer chassis.  If it is not pitted, it might clean up very nicely.


I wouldn't use steel wool anywhere near an amplifier or radio chassis.

I think the reasoning is primarily that steel wool can leave little steel fragments that can conduct and short things out.  If you choose to use it, do so with great care and sparingly, looking out to make sure the debris doesn't migrate.  Maybe use a vacuum cleaner to make sure you recover any debris.  On boats, the usual rule is to use bronze wool to avoid leaving little slivers of steel that will rust.  But bronze will conduct at least as well, probably better than steel.

Chris Campbell


19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #12 on: November 30, 2017, 07:46:11 PM »
I'll be careful.   The unit means a lot to me.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Motorola Minion

  • Hero Member
  • *****
  • Posts: 701
  • Southern Pennsylvania
    • View Profile
Re: Unknown Model
« Reply #13 on: December 01, 2017, 01:20:38 PM »
Congratulations, I was hoping you would get it. the model sticker on mine was stuck inside the cabinet, on the back of the record compartment. Date was on the side. Happy Hunting!
Tubes - Magical - Tubes

Dave

19and41

  • Sr. Member
  • ****
  • Posts: 448
    • View Profile
Re: Unknown Model
« Reply #14 on: December 02, 2017, 04:18:59 PM »
Thank you.  I have removed the receiver and though much of it is pretty clean, the dial glass has a layer of atmospheric scum on it.  Has anyone cleaned one of these?  The background material has lint and dust on it.  I have managed to clean the fascia for the receiver.  It had splotches of something on it that would only come off with isopropyl alcohol. It's clean but hazy.  Would it be possible for a moderator or administrator to change the title of this therad to Magnavox 1-ST621 ? I'm pretty sure that is it's model number. 
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke


Sorry, this topic is locked. Only admins and moderators can reply.