Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Motorola Minion

Pages: [1] 2 3 ... 34
1
Motorola / Re: Motorola Stereophonic restoration at last
« on: June 23, 2017, 04:52:09 PM »
First, I measured the resistors and found all to be within spec. I also checked the primary resistance on all three output transformers, hoping for the best and all were close to resistances on the schematic.  ;D

Most Motorola products work as found due in no small part to the extensive use of ceramic disc caps in place of wax-paper caps for values .001 through .05 in. But due to effects of temperature and vibration on capacitance, ceramics have limitations in coupling and emphasis'/de-emp networks. Mylar film caps will replace them as I have done with two of my Magnavox amps.

The amp chassis is pretty shallow, so installing electrolytics under it requires some careful placement and the use of a 5-lug strip. this should be pretty clean when its done and I will label the caps with half-circle, square, triangle and dash to match the 4-section can designations, also shown on the Sams schematic.

Typically, I solder all the film caps across the ceramics, then cut them out when trimming all the leads. It ensures I double check old and new values before removal.


2
Sightings / Re: CL: 1958 Fisher C-800 $350 -- San Diego, CA
« on: June 22, 2017, 02:08:15 PM »
Damn, $50 is a steal for this!!


Wish I had room for it right now... I'm driving right past there to go to a wedding on Saturday too...

You can always squeeze one into your vehicle and just drive around with it for a few weeks until you figure out what to do at home.

With what California means to old cars I'm surprised there is not much knowledge about Fisher's among others. This would have been gone in a flash almost anywhere on the East coast.

3
The Custom Electra is right in the middle. This is a mostly tube set as you surmised.

I have a VII, the year before this, that is all-tube. The Custom Electra had option in the 1964 catalog for solid state amp chassis. Jon at fisherconsoles.com maintains lots of great information.

I'm not sure how pricey Fisher's are on the west coast but I have picked some up locally (not many HiFi nuts here in lower Pennsyl-tucky) that were just too cheap to ignore.
One is a 1966  Electra E-491 and 1967 Statesman both all solid state with Dual 1009/1010 record changers. Both also need lots of my time but should turn out OK. I grew up with a Dual 1009, so any console that has one is an automatic favorite of mine.

4
Sightings / Elvis had a 1971 Magnavox
« on: June 21, 2017, 02:32:01 PM »
 https://lancaster.craigslist.org/ele/6183909630.html and https://lancaster.craigslist.org/atq/6184906594.html

In case the ad is gone, http://auction.graceland.com/1971_elvis_presley_owned_magnavox_stereo_from_his_-lot324.aspx

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.

5
The Motorola consoles seem to work as found, often with no work having been done, not even tubes.

The fact I am working on one of these (insides anyway :D) right now, Id guess nobody wants to take a Motorola apart to do the most basic of maintenance.

6
Motorola / Re: Motorola Stereophonic restoration at last
« on: June 20, 2017, 04:16:31 PM »
Some pictures

Hardware removed and cleaned up, making it look a bit better

The Multiplex adapter next to the amp, look at all those wires - tags are mandatory unless you like figuring it out yourself from the schematic.

All apart on the floor, the amp is now on the bench for tomorrow. Ill take more pictures of just that.

Early summer mornings it is cool in my shop, and the only way to get uninterrupted time to work on this fun stuff.

7
Motorola / Re: Motorola Stereophonic restoration at last
« on: June 20, 2017, 04:13:12 PM »

[/quote]

If you seal up the woofer, won't you change its resonance and mess up the overall balance designed into the system?  If it's easy to do it wouldn't hurt to try, but it's likely designed for infinite baffle/open box use.

Chris Campbell
[/quote]

Sounds like maybe the cabinet is all it needs to be. This is not a Drexel or Heritage cabinet like the more expensive units but these are the exact same components that would be used in the high-end furniture.

8
Chat / Re: No such thing....
« on: June 19, 2017, 04:14:05 PM »
It appears insurance or bonding might be the ticket to road use as opposed to making your cart DOT compliant.  It makes me wonder what measures the Amish have to undertake to get street legal.

After moving 20 years ago, we are surrounded by Amish. Those buggies, while having minimal safety equipment, must have the triangle reflector. if they're out at night, head and marker lights comparable to a motorized vehicle. Improvements are ongoing with LED lights on almost all carriages anymore. Believe it or not, the gray buggies seen in our area go for $5000 or more. Going to a horse auction is amusing as it sounds like the announcer is talking about a car. Nice family horse, ran him/her up to (place 30 miles away) with no hair-raising moments and only gentle pulls on reins kept it straight. Not excitable when there is lots of pedestrians, bikes or obnoxiously noisy motorcyclists...

Many times, I will be in the garage and hear the thump-thump of a sub-woofer go by, slowly, and when I look I can see the buggy lights dim to the beat. Rumspringa is in high season here ya know.

9
To finish the last post, I would go very slowly and check your work after every few parts you change. The power supply caps are #1 as all here would agree. There is a service manual for your console on fisherconsoles.com has much helpful information. Justradios and mouser, allied or capacitor world can help you with parts but you must change them and then play it again to see some improvement. your hum will probably be gone but improvements are possible.

My E49 amp-tuner are sitting for the time being while I work on its cabinet and Garrard changer. When I looked at it, the seller plugged it, against my advice and yes it was playing a bit, through the awful hum. ::) Most of the work to date is detailed here   http://vintagehifi.net/index.php/topic,1812.0.html

10
Tube Consoles / Re: Magnavox Berkeley - CR198 chassis restoration
« on: June 19, 2017, 02:29:56 PM »
My frequency counter is not functioning, so I have to get a digital scanner to calibrate my not-so-accurate generator evenly at 10.625, 10.7, 10.775 MC.

Get an HP frequency generator and never worry about that again my man.

I agree, just need the $$$. My B+K 1801 freq counter has a working nixie tube display, but it does not read properly.

11
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 http://vintagehifi.net/index.php/topic,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.

12
Introductions / Re: Noob from Central Illinois
« on: June 19, 2017, 11:44:17 AM »
Welcome to vintage Hifi (VHF) I briefly had an RCA like yours and all I did was clean all switches and pots with DeOxit, and it responded well. That record changer is hands -down better than the standard BSR's everyone used later on in the mid 70s

I recall its FM reception was not too good until an external antenna was connected. Here we have a crowded FM dial, and many times the built-in dipole is just put in a bad position even for a strong signal. A simple dipole of 32 inches for each side seems to work well when placed in the attic - above all the metal stuff in a garage..

13
As the owner of a Fisher Custom Electra 7, two years newer, I can confirm these are a bit tougher than your average tube consoles. The capacitors will need to be replaced of course, but you will also find that resistors will be dead on

14
Tube Consoles / Re: Magnavox Berkeley - CR198 chassis restoration
« on: June 19, 2017, 10:32:37 AM »
After a few listening events with this receiver, I have noticed a few things that bear mentioning.
1. The FM chassis (CR192) is a fine addition except for its Foster-Seeley discriminator. After making the adjustments as per the service manual, with an AM signal varied from 10.625 to 10.775, the on-station FM reception was pretty fussy. You have to tune right and left of not-so-strong stations to minimize the distortion. I needed to make some by-ear adjustment to the top and bottom on the discriminator. This was early FM and a ratio detector is a huge improvement.
2. The AM-SW is a great receiver with a built-in loop. I was able to find a station with music and noted how, even with a weak daytime AM signal, it sounded almost as good as FM. Finding a SW station is easy but a few feet of external antenna is needed to minimize the fading common to the 31 meter and similar bands.

15
Sightings / Re: RCA SHF-3 - $150 OBO--- Gilbert, Arizona
« on: June 12, 2017, 11:38:20 AM »
Such a reasonable price. I really like RCA but so few seem to show up locally compared to Zenith and Magnavox. Thanks for posting.

Pages: [1] 2 3 ... 34