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Topics - Motorola Minion

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Sightings / Webcor Musicale Coronet - PA
« on: December 01, 2017, 01:17:00 PM »

Electronics / OEM caps measure high - PB solid state pre-amp
« on: November 21, 2017, 11:31:43 AM »
While working on the preamp section of a 1966 Packard Bell Console RPC-66, covered by SAMS 902, I have found some common Nichicon caps, the last few I need to replace.

The problem: C315 and C316 are labeled as 25 mf @ 3 volt and measured 124ufd (!) on a Fluke DMM.

C317, 318 and 319 labeled 50 uf @ 6V measured 221 ufd. I will double check on the EICO 950 but expect the same and checking for breakdown voltage, which the 950 does up to 500v, on a 6 volt cap is just impractical.

Note that my intended new replacement caps, measure 26 and 48 uf respectively. I'm used to original parts measuring lower, but not this.

Do these caps fail by increasing in capacitance? I expected a decrease in capacitance attendant with an increase of ESR.

Consolettes / General Electric and porta-fi
« on: October 05, 2017, 08:57:07 PM »
Its not good to have a year since the last post in a forum but this is one is asking if any one has a GE in that wall-mounted cabinet with either a Garrard or GE changer.

I recall their early solid state amps mated to tube tuners on some. 16 ohm speakers ?

Other Solid State Console Brands / Packard Bell RPC-66
« on: October 02, 2017, 11:30:03 AM »
I'm working on this solid state console that probably needs caps among other items. The voice of music changer is branded PB also but uses an odd cart.

Has anyone here worked on a PB before. I have a Sams 905 for the RPC-56, hoping its close. Pictures once I open it up.

RCA / RCA Victor VCR-244
« on: September 21, 2017, 03:18:13 PM »
I got this about 2 years ago along with a Sylvania SS console for $40 with some other stuff. I was not in a hurry to find out how bad it was inside after I read Larry's thread on one in similar condition. I was pretty sure I would get around to it soon and then a second and much better condition RCA 3VF516 showed up.

So I decided to take it and sell it along with my usual selection of old radio/tv stuff so I took it to the twice a year, mostly antique radio swap meet at Renninger's in Kutztown PA. I got a few questions but nobody bit, so that is the last damn console I'm taking there. I was also glad I did not take the 1964 Admiral there again, since the guy from Arizona that wanted it (but had no room) last year did not show up this time.   

Then...I saw an article in a 1960 PF reporter on phantom 3rd channel stereophonics, showing the various design approaches by Zenith, Motorola, CM, Webcor and others. RCA's design looked interesting and because my other RCA is straight stereo, I decided to plunge into this. Pulling the tuner and amp out tomorrow.

Tube Consoles / Stereophonic 3 channel document uploaded
« on: September 21, 2017, 09:41:47 AM »
An article from a 1960 magazine "PF reporter" on how the various manufacturers achieve the phantom 3rd channel. Since Magnavox did not participate in this development, it is in downloads of other manufacturers.

Tube Consoles / High Fidelity document uploaded
« on: September 21, 2017, 08:53:01 AM »
A Motorola Distributor complied a booklet "the growth of sound" on Stereophonic High Fidelity that is a must-read for any tube console or HiFi owner.

If you are logged in as a member, click the "downloads" tab on the very top of the webpage.

Other Tube Console Brands / Philco H1619 - small stereo console
« on: September 01, 2017, 11:45:27 AM »
Picked up a small console yesterday from a CL ad that had no picture. Normally I do not bother but the mention of tubes and $20 price had me thinking I should.

The amp has only two single-ended 6AQ5 and two 6AU6 as pentode-connected preamps, but this transformer amp beats many others in this price range that simply have one 12AX7 and two 50C5, with NO transformer. The record changer is a Voice of Music

This 1960 came with documents I plan to upload to the "downloads". The 1960 stereophonic brochure is a great find, because I also have one of the more interesting models (four 6BQ5 and electrostatic) as an unrestored keeper.

Pics with next post

I do not have a Sams to refer to, but how is tracking force adjusted?

The cartridge hinges in the tone arm at the back of the head, so if the arm tracks too heavy, the push-in white retaining clip rides on the record instead of the stylus. I hack-fixed it by placing some tissue paper on top of the cart to limit its upward movement. It plays well but tracks over 8g, too much for a 2-4g stylus.

The tonearm is too heavy and only a shaft screw and spring hold the arm on. No counterweights, but maybe that's an option to add them.

I have a spare one of these changers from a VLT51 1968 Ann Arbor. Looking at both it and the one I'm restoring, I see nothing besides a fixed spring that can affect tracking force.

Astrosonic and Other SS Magnavox's / Magnavox estate sale leftover
« on: August 28, 2017, 01:22:32 PM »
A friend of mine that has no interest in consoles spotted this 1968 Early American Astro-Sonic at an estate sale and later saw it did not sell. Its a nice, dry and sunny day, so he brought it with him now its in my pickup. When I get home Ill get better pictures when I open it up. Although I prefer older tube models, this will likely be easy to make functional and last another 50 years. Twice already, I have traded a working SS console for a barely working but more desirable tubed Magnavox in great shape at thrift and used furniture stores. Win-Win :D

Unfortunately for us mid-Atlantic collectors, all the Imperials and 100-watt Astrosonic models seem to be on the west coast. The good thing is, anything we do find is very clean.

This is tagged Model 1P3622, and I'm guessing is a 20 or 30 watt receiver with 12" LF drivers and horns.

But cannot seem to find this model in the catalogs in downloads. If the numbers are close, it is probably a variant of the 1P3621 found in the 1968 catalog. Third attachment, paragraph A.

RCA / RCA console - lower and upper speaker enclosure
« on: August 16, 2017, 02:18:57 PM »
Has anyone seen one like this? I bet Larry has. It is of the 1963-64 style, as opposed to the earlier non-multiplex FM sets. Its great to see the other variations posted in this forum.

I am picking this up Friday and cannot wait to see what's inside. Are there high-frequency speakers or horns in the upper part? I'll have to move some out and maybe donate others to make room.

Tube Consoles / 1963 Grundig KS590
« on: July 25, 2017, 10:36:14 AM »
I debated if this should go under Sightings but I already agreed to buy it. It has six speakers, push-pull EL84 stereo amp, and a multiplex adapter. I have no fear of German stuff, as an electronic nut, knowing what the discrete components look like is that hardest part.

I must be the only local who would give this unit what it needs, a cleaning and electronic restoration. I looked at it 2 weeks ago and its in a backyard storage shed, but dry thank goodness. the seller contacted me an asked if I was still interested.

 Unfortunately the reel-2-reel player is long gone but the Dual 1009 record changer is original. A tube and preamp capable of amplifying a magnetic cartridge is only something I have in a Fisher that needs almost the same level (total) restoration :(

Here is the changer from my 1947 Berkeley. Obviously this was an upgrade to play newer records and it has an E-V 26, stereo cartridge. It is in good physical shape but lots of dust has lodged under and in the mechanism, so I have spent effort cleaning it. I just disassembled/cleaned/lubed bearings on the motor and replaced the conical rubber motor mount bushings. It is plenty torquey and sits just right where it should, vertically lining up with the drive pulleys, which are supple and pliant.  It looks like the British-made Micromatics I'm used to like the later W602's but other things are not at all similar and I have a few questions and hope someone here can give benefit of experience. 

The cycle wheel/gear must be removed so its shaft can be lubricated just like on later Magnavox but it looks like 5 Philips screws on top side, around the spindle area and tone-arm, need to come out to drop the entire changing mechanism. Before I take the step of this much disassembly, is it necessary to thoroughly clean and lube the changer?

A second issue is the idler wheel that drives the platter. It seems not able to move far enough horizontally to engage the capstan on the motor. Is there a "release action" like on V-M changers that allows it to swing over?

Sightings / Elvis had a 1971 Magnavox
« on: June 21, 2017, 02:32:01 PM » and

In case the ad is gone,

BTW, I happen to be restoring one of these and just got the record changer done. I was afraid I wouldn't have any interest if I posted an ad :-\ but it looks like someone, local no less, just beat me to it.

Motorola / Motorola Stereophonic restoration at last
« on: June 19, 2017, 12:34:12 PM »
Quality sound is needed to serenade all the flooring and painting work. So I got this,1559.0.html from CL almost 2 years ago and has been sitting in the rec-room attic of an addition I started about that time. Also at that time, I began working on a 1964 Fisher Custom Electra for this event, but since moved it to the garage because the Italian Provincial cabinet needs to be stripped. I also need to repair its Garrard changer and power switch though its amp and tuner are all cleaned up and recapped.

Back to the Motorola. ONE bit of advice if you work on one is to LABEL ALL PLUGS and SPEAKER WIRES before you attempt to disconnect anything. And you have to undo the whole business to work on any one chassis. I will add some photos of how I used "brady tags" to assign numbers to all these plugs and leads. Unlike Magnavox, RCA and Zenith, Motorola seemed to separate all the components. Placing the preamp in its own sealed chassis is pretty neat though.  ;)

The 3-channel amp has the power supply on it as well. The power is distributed to a tuner, a preamp and the FM multiplex adaptor. Speaker leads and an RCA plug are on the verbaphonic reverb unit, which is made by a supplier to Hammond Organ. Looking at the Sams schematic does explain all the routing but when you actually look inside one of these consoles, you will be impressed and intimidated. I swear there is more wiring (though neatly routed and tied) than in a VW Beetle  ???

After labeling all the plugs including speaker wires, I disconnected them and put each chassis into its own flat box. This will allow each to be carried down to my bench and I can place all related hardware, cables, spent parts in the box as I work on it. First one up is the amp.

I also gave the cherry veneer finish (not a Drexel cabinet) a good cleaning of dirt and old wax using 000 steel wool and turpentine. The drawer hardware was removed and will probably end up in a bag inside the cabinet, since early American style needs all the aesthetic help it can get.

Last night I decided to pull out all five speakers to check physical condition and to test them and the crossover caps on my audio oscillator. The 12" woofer was pretty even (by ear) from about 36 Hz up to 500 Hz. The 8-inch midranges made noise from 400 to 6000 Hz and the 3.5" cone tweeters were clean from 5K until my ear's limit of 12K. I put them back in and wonder if maybe that 12" woofer should have its own air-suspension box built into the cabinet.  :-\

Ill post all the electronic restoration here rather than in repairs because I do not expect anything unusual.

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