View Full Version : Magnavox Astro-Sonic Combo Is Complete
ARC Tech-109 09-09-2006, 12:29 AM Well this evening I put the finishing touches on my Astro-Sonic combo set and I gotta tell ya it works great! Before I start in with all of what I had done I want to thank all the members especially Randy Bassham who pointed me in the right direction with the exact chassis number of the TV receiver itself.
So far I have replaced the Pix tube twice, original was very weak to begin with and the second tube would loose the green gun over a few days time if left in the instant on position. I could shoot it with my B&K 467 but it would fall down again and the last dusting of the gun turned into a K+G1 short. Ended up dropping in another 25XP22 NOS tube.
Ive also replaced all of the resistors on the horiz/vert/pin board, most of the resistors on the video board and several on the IF strip along with clipping out the OE supply caps and subbing in 450v low-loss photo caps. All the tubes are NOS american mades along with what I suspect are Telefunkin 6GH8's in the chroma circuits.
Now I know this is gonna upset a few purists but I also added an older FRED MTS decoder and tapped off the sound IF to feed it, split the mixed audio line in the stereo receiver for TV and subbed the solid state amp with a Heathkit AA-100 chassis right under the turntable. The output transistors were shorted along with several drivers up the chain, my opinion is the set should have had a tube amp in the first place. Its a lowboy console not the upright so I have plenty of room and besides the tubes sound great driving alnico speakers anyway. The turntable works great but the auto changer is still a bit stiff, heck even the old ultrasonic remote works great for both the set and my dog.
Ready for the clincher? I recently had a lightning strike on my property of 15 acres, a tree near the house was hit and the resulting spike took out the 1N34 chroma phase detect diodes along with the horiz AFC diodes along with many other solid state things in my home. Being Germanium devices and no access to these animals I instead subbed in 6AL5s and gained a little on the chroma stability and alot in the horiz AFC stability. I can now play a VHS tape from a crummy late model VCR and not have the flag waving at the top as I did before. This thing is rock stable and even the UHF has slightly better sensitivity, Im 36 miles away from our "transmitter central" in Shoreview/Arden Hills MN and knowing where our UHF stations transmit just getting a signal where Im at is a job in itself. For those in the MPLS area KTCI-17, CW-23 and 29 all broadcast from the channel-9 tower that is located east of the twin towers along with all the FM broadcasts. The UHFs are patterned south and west of the tower with a -9db null at 40 degrees from due north. If you want more details on the stations private message me as I do alot of work for the broadcasters and know the techs.
Im going to work on getting some images of the set into the forum so you guys can see how nuts I really am. Dont know what resolution they will end up at but I will try to keep the details sharp, then I move on to my Works In A Drawer that needs the wires dressed.
Thanks again to everyone!
109
jpdylon 09-09-2006, 01:36 AM awesome! can't wait to see those pics.
ARC Tech-109 09-24-2006, 10:05 PM HELP!!! For the better part of a week I have been *trying* to upload pictures of my AstroSonic along with my completed Works in your Drawers but the only thing I get is the "Uploading" message until hell freezes over or I loose my connection. Ive tried 640x480 and other sizes but only with the same results? Is Audiokarma biased against Magnavox and Motorola sets? Do I need to put the original stick rectifier back into the Motorola HV section and use the 3A3 for something else? Am I loosing my mind? Anyway Im having a heck of a time here.
109
JCFitz 09-25-2006, 06:37 AM If you're using dialup you may have to send only 1 picture at a time.
ARC Tech-109 09-25-2006, 08:46 PM I keep getting "Unable to create image [/var/www/vhosts/audiokarma.org/httpdocs/gallery/uploads/16267/IMAGE031.jpg].
Please contact system administrator."
Guess it doesn't like my combo after all :no:
Going to try something else for the time being
109
captainmoody 09-25-2006, 09:02 PM Is this what your combo looks like? Love mine, Sounds like yours really performs! I prefer mine unmodified and factory original though.
ARC Tech-109 09-25-2006, 09:16 PM Looks similar to yours Moody but mine has the sliding wood doors over the CRT and is a bit wider and I'm sure heavier. I had little choice but to deviate from stock form as I couldn't find the correct output transistors for the original amplifier and the service manual shows a different stereo receiver only outlining a 30 watt version in an upright "bookcase" type cabinet. I added the stereo MTS decoder at the request of my kid and I had to agree with him, it was capable and no holes had to be drilled so returning to stock would be very easy.
Now Ive tried to upload some of my images to the users side of AO-hell but even that is biased against my magnavox so Im going to try as an attachment to this post, lets see if it works!
Ok YES it works! That is my daily watcher that started its life off in a smoke filled apartment in Bloomington MN then moved to a barn in Rogers MN where it sat for around 10 or so years then moved to my home on July 04, 06 where it will stay. I like to keep my stuff forever or at least as long as I can. The pioneer SX and Technics CD player have been owned by me since new and bought with my paper route earnings along with working at a high-end audio store during my early teen years. My motto is simple: If it works why replace it?
More pix to come as I crop them to being dial-up friendly
109
captainmoody 09-25-2006, 09:49 PM Yup, similar cabinet. Mine has the sliding doors as well.
ARC Tech-109 09-25-2006, 10:16 PM I looked closer at your combo and noticed the sliding doors are actually cloth covered and cover the speakers, VERY cool touch on yours.
Do you know cabinets? I have no idea what "series" mine is as far as styling is concerned. I do plan to strip and refinish the cabinet for my set as the finish now had become saturated with cigar smoke and a few water rings on the top.
Those KLH speakers in my first photo was my first attempt at a veneer job. I found those speakers sitting next to a trash can in 1987 after a storm dumped nearly 8 inches of rain in one night. They looked like bannana peels but a few weeks in my fathers wood shop he taught me the art of veneer so I plan to do walnut veneer inserts over the poplar hardwood used for the sliding doors and top panel. Dad is an expert cabinet maker among other trades and he loves doing this sort of thing.
Thanks for the look
109
Pioneer727 09-26-2006, 02:52 PM I just recived a Magnavox Astro-sonic 615 for my Birthday Its in Mint shape sounds Great thu no TV just AM/FM and record player I guess its from 1965. Everything Works. Yours Is Great Looking too . :thmbsp:
Ron
ARC Tech-109 09-26-2006, 10:31 PM I actually like those old console stereos or HiFi's as they were known. My grandmother used to have a Magnavox but dont remember the model or series. Do know it used 6V6's in the outputs and had a turntable and seperate speaker that was similar to the main unit. I can remember her getting wild with that thing playing old Elvis, Hank Williams or whatever she could grab ahold of at the time, think I was maybe 4 or 5 years old. I do remember that thing could bark quite well.
109
Pioneer727 09-27-2006, 07:08 AM Mine sounds Good will sound better after I replace some Caps hehe . I am trying to find a needle for the MicroMatic turntable at Needle Doctor wish me luck
Ron
ha1156w 09-27-2006, 05:08 PM The best way to reference the stylus is to drop the cartridge -- one screw on the underside of the tonearm. On the top should be the cartridge model number. Even if the stylus "looks" right, there are lots of nuances that will bite you in the tail for a mismatch. I know that the EV285 and EV275 they used to use are different in an eyestrainingly small ridge that makes all the difference as to whether the stylus fits or pops back out mid-record. I've had good luck finding new stylii on eBay if you can't get it through the normal channels. Also try Needle-In-A-Haystack too. They have lots of inventory last time I dealt with them.
Pioneer727 09-27-2006, 07:18 PM I popped the cart and found Electro Voice Model 453. Sent a Email with a pic of the needle and cart model # to Garage A records and he found a model 357 thats looks just like it. I will check your link Thanks
Ron
ARC Tech-109 10-01-2006, 01:46 AM Just a few pics I snapped off today while cleaning up the convergance, the purity rings were getting a bit weak and purity was starting to suffer. Think it all started when I demag'd the set and went across the back with a live loop. Oh well Im far from perfect. Enjoy the pics
Sorry I didn't vacuum the floor, didn't feel like dragging out the old Kirby 508
109
blue_lateral 10-01-2006, 02:20 AM Thats a beautiful set. Nice work. :thmbsp:
John
ARC Tech-109 10-01-2006, 11:39 AM Im still having trouble with blue tilt in the top portion of the screen, I can warp the lines like a sinewave but never quite get the vert convergance perfect. I spent the better part of the day going through the procedure, replaced the caps and a few resistors but nothing helped. Oh well I might have to live with it or play with it more when the snow flys.
109
ARC Tech-109 10-04-2006, 11:46 PM Got the issue solved and if anyone else is having a similar problem replace the "diode cube" on the convergance board, replace it with single 1N4007's following the schematic.
One benefit of my combo is the amount of heat generated by the set. I got to watch a solid 3 hours of TV this evening and noticed the temp in the house went UP by a few degrees. Figuring the 550 watts thats sucked in maybe 2-5% is actually in the form of CRT light and sound to the speakers with the balance coming out as heat I figure this to be in the area of 1800 BTU of useful heat energy. Sure keeps the living room toasty especially now that our local temps have fallen into the 40s at night.
109
Zenith26kc20 06-17-2009, 12:47 PM Looks like a T933! I just sent my CRT to Scotty at Hawkeye after it got tired (original one). Watch your horizontal output current. If too high it'll be slow death for the flyback! I find these sets have a "sense of humor". Mines had some quirky problems and seems to enjoy making me work for a solution. The best was a intermittant short in the third IF tube. Off channel snow would come and go! Some fun!!
Jeffhs 06-17-2009, 02:43 PM My motto is simple: If it works why replace it? 109
Your Magnavox Astro-Sonic TV looks great, and I bet it sounds wonderful as well. Magnavox really knew its onions when it designed those Astro-Sonic consoles back in the day.
I'd keep that set as long as it works. Is it all-channel or just VHF 2-13? I'd say the latter, as the radio tuning dial is marked with kc and mc rather than MHz and kHz. The latter replaced kc and mc in 1967, so I think your console must date back to the early '60s.
If the CRT is good in your set, it should serve you well for many years to come (even now that all TV is digital, your set should work very well with a converter box). They don't make them like that anymore, like Zenith TV and stereo. These were two of the best TV and combination manufacturers before they went overseas. We will never, unfortunately, see the kind of quality (of build, sound and picture) found in old Magnavox's or Zeniths again. :no:
"If it works, why replace it?" is my motto as well. I have a 14-year-old Zenith Sentry 2 19" TV in my bedroom with original CRT, never any service done on it, and an excellent picture, a 9-year-old RCA XL-100 CTC185 (also with the original tube and a great picture) and only two small (but expensive) repairs done on it, in the living room, a 9-year-old Aiwa all-in-one bookshelf stereo with CD player (only thing wrong with it is the cassette decks quit a couple years ago; replaced them with a 30+-year-old Radio Shack SCT-11 stereo single-cassette deck), my computer (and its Win98SE operating system) also has nine years on it and it still does everything I need it to do (including playing my CDs through my Winamp 5.35 media player) even though the computer is slower than molasses in June, so I have no intention of replacing it any time soon, or at least as long as it works. Every bit of this stuff was brand new nine years ago (bought it all the year I moved to this apartment) and, surprisingly, as I said, most of it still works almost as well as when it was new. I intend to run it "until the wheels fall off", as the expression goes.
rockin1150 06-17-2009, 03:18 PM bitchin' I can see the appeal here.
zenithfan1 06-17-2009, 03:54 PM Jeff, this set is from 1968. I used to have the EXACT same one, I miss it. For some reason, Maggie decided to hold onto the old markings for AM and FM longer than other manufacturers.
|
|