Author Topic: Magnavox 1-ST-621 Danish Classic  (Read 1140 times)

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #15 on: February 22, 2018, 08:27:07 PM »
Another good forum is vintagehifi.net .  They have a lot of reference material as well.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #16 on: March 10, 2018, 04:18:55 PM »
Well, I finally got it up and running.  An excrescence sitting in the middle of my living room.  I've set it up with the music library and it is shaking the walls and rattling the windows.

I meant to say it was an excrescence before it was up and running.
 
« Last Edit: March 13, 2018, 01:28:29 PM by 19and41 »
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #17 on: March 19, 2018, 12:31:47 PM »
Over a period of operation, the FM receiver has gone off frequency.  Way off frequency.  It is missing 1/3 of it's bandspread.  I had bought another receiver a few weeks ago, so I set it up to use in this console.  It's closer to being on frequency and has the entire bandspread.  I gave the unit a application of orange oil.  It is looking better.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #18 on: April 03, 2018, 05:32:15 PM »
I got the original receiver out, and set it up to connect into the system while having it fully accessible on a panavise base on a small stand.  I can get some movement on the received stations but I am going to have to get an indicator of my alignment of it.  It looks like a digital oscilloscope interface for a PC/Laptop would come cheaper than a VTVM.  I prefer a scope anyway. I have a conventional scope, but it is only 10 Mhz, below the FM IF for this unit.  The alignment relies on both symmetry as well as amplitude as the indicator of correct alignment.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #19 on: April 06, 2018, 08:30:59 PM »
I've ordered a 20 Mhz digital scope interface and some ceramic caps and some metal film resistors.  I should have something going on soon.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline Babybearjs

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #20 on: April 06, 2018, 09:38:42 PM »
these old sets are expensive to restore and near impossible to find a needle for the turntable. My cousin has an old 1950's stereo and the tuner in in the shop....at $70.00/Hr for labor, you'd better really want these units to work....
John

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #21 on: April 06, 2018, 09:58:03 PM »
That's where doing your own repair work makes things much more affordable.  There are a number of businesses that carry needles, drive parts and other bits for phonographs.  There are a few places still manufacturing the vacuum tubes (valves) for these units as well.  This console will play recorded music very well, it's just the FM receiver that is having some problems.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #22 on: April 13, 2018, 07:20:31 PM »
I had ordered a set of ceramic alignment screwdrivers to use when the oscilloscope finally gets here.  The metal film resistors came from China and spent over a week in customs in Frisco.  The ceramic capacitors came from Amazon and was here in 2 days.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #23 on: April 17, 2018, 01:43:54 PM »
Got the oscilloscope and couldn't get any useful function out of it, so had to lug out the CRT oscilloscope and set up to align the unit.  The original receiver wouldn't correct from the strange condition that it had.  the spare that i ordered was able to center up for much of the bandspread with the last 10-15 Mhz off scale.  The unit does sound quite nice.  I can strongly recommend a set of ceramic alignment tools for RF alignment work, as they performed quite well here.  I have a return request initiated on the new oscilloscope.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline 19and41

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Re: Magnavox 1-ST-621 Danish Classic
« Reply #24 on: May 21, 2018, 01:57:01 PM »
The receiver has been tweaked and peaked up for a while now.  It appears the next problem with it is my being in a non line of sight area out of town.  I have ordered a amplifies AM/FM antenna for it.  My vehicles' radios seem to work well in the driveway, so I should be able to get a decent signal at home.  The console just has a time with the afc hunting and MPX locking.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke