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Messages - SeniorSteve

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Other Tube Console Brands / Re: Unknown console
« on: February 21, 2019, 02:41:35 PM »
Here's a picture of a Fisher that looks very similar to the one in your picture.

Other Tube Console Brands / Re: Unknown console
« on: February 21, 2019, 02:34:58 PM »
Could it be a Fisher?  I know they had many different cabinet styles that had doors over the speakers.  Early to mid 60's is the vibe I get from the cabinet.  In any case it looks very nice.


Magnificent Magnavox / Re: Concert Grand
« on: February 21, 2019, 11:31:11 AM »
The end of the 50's I believe is when they changed from the Conquest to the Micromatic, but it's still a Collaro changer.  I can't say for sure what would be in your CG, I don't know the Magnavox line up like some on here.  The operation is the same I believe, as it taps the side of the record to determine size.  If it's like the Micromatic I like the fact that the change drive isn't taken from the platter, but a different idler off of the motor.  This means the change cycle speed is the same in 16 as it is on 78.  In any case the Collaro changers are well respected. 


Magnificent Magnavox / Re: Magnavox 1P3700
« on: February 15, 2019, 10:24:19 AM »
One thing you have going for you is there are two channels and you can compare them.  First thing I would check is to see if the voltage is correct on the output stage.  The case (collector ) of the transistors are a good start, one should be the supply voltage and the other transistor in the channel should be at half the voltage (36 and 18 volts respectively).  This isn't a guarantee that it's working, but tells you that the DC parameters of the output stage is normal.  If those voltages are within reason, the next step would be to see if there is an AC signal at the output stage.  Turn the volume up to a normal listening level and put your meter on AC volts then measure the ac voltage on the collector terminal of the output transistor with the lower DC voltage.  You might run into several volts here, but the main takeaway is you should have similar voltages on both transistors with the lower collector voltage.  I've run into the output coupling capacitors open with the result of a "dead" channel.

Something else you can try to eliminate some of the circuitry is to feed a CD player into the "Tape output or monitor"  jacks.  I'm not talking about the "Tape Input" jacks on the back of the console.  This is essentially connecting the player to the volume control, bypassing the selector switch and first two transistors in the amp.  What you are looking for is consistency between the channels.  They may be very low volume or not sounding that good, but they should be similar.

Let us know what you find out.


Magnificent Magnavox / Re: Magnavox 1P3700
« on: February 14, 2019, 10:51:02 AM »
I just looked at the schematic and it does use the more expensive germanium transistors for the outputs.  I have found that most of the time they are good and it's something else.  Is there any noise or hum coming out of the bad side, (you may have to put your ear up to the speaker to check).  If it has a speaker selector switch, run it through the positions several times, the contacts get oxidized and scratchy like volume controls.  The setting it should be one at this time should be "Int" or "Internal".  Once that is checked we will have to find out how comfortable you are taking voltage measurements inside.  The thing that breaks these sets is when you connect up external speakers and the terminals get shorted together.

If we know your experience level we can help you better.


Magnificent Magnavox / Re: Magnavox 1P3700
« on: February 14, 2019, 10:35:56 AM »
I just downloaded the file, and changed the extension from php to pdf.  The file opens up fine.


Hi Chris, it's another way of saying I went "off topic".  In this case I hope it was only a little bit.  Sorry everyone.


Hi Bill, I listen to my AS225a speakers quite a bit, they are superb for pipe organ music!  Not to threadcrap, here is the Sylvania receiver I have (it's still keeping in the same brand).  This was my first high quality stereo system when I was growing up, it was quite expensive.  Sylvania matched their top of the line system with the Dual 1225 I believe.  I had one of those as well, but didn't know how to fix them, so I got rid of that piece.  I wished I had kept that.  The RQ xxxx line were the 4 channel line of receivers (RQ3748) was quite popular. 

Sylvania was a good brand in the 60's and 70's.  The dealer I worked for in the 70's sold Zenith and Sylvania.  I was one of the radio/tv/stereo repair technicians, and there were far fewer service calls for the Sylvania TV sets over Zenith.  I remember there was a massive recall for a 4 legged capacitor for the Zeniths.  If not replaced, you had a good chance of the picture tube cracking because the high voltage would spike and destroy them.  If you sat them side by side, I actually like the color of the Sylvania better.

Bill, I still have a pair of AS225a speakers and the Sylvania receiver RS4744 (60WPC) that I purchased in the mid 70s.  Just recently recapped the receiver and it sounds great!!  At the time it was owned by GTE.

Chat / Re: The old GE radio
« on: February 04, 2019, 01:29:10 PM »
I'll agree with Greg in the fact you shouldn't see any glow on the plate of the 6L6.  One thing you want to check is, the bias on the output tube.  That voltage is developed across R-26 (110 ohm),and R-25 (10 ohm).  One way to check this would be connect one lead of your meter to the center tap of the HV winding (negative side of the filter capacitors), and one side of the meter to chassis ground.  The center tap of the HV winding is the most negative point in the radio power supply. You can also check both of those resistors by checking continuity between the same points, you should read about 120 ohms total (radio off).  You can also check bias right at the tube by checking voltage between pins 5 and 8 on the 6L6.  The more negative voltage will be on pin 5 since pin 8 will be connected to the chassis.  The voltage across the combined R-25 and R-26 should be very close as the voltage between pins 5 and 8 on the 6L6. 

Ballpark figures for voltage would be between -15 and -20 volts.  As the grid becomes less negative, more current will flow through the tube.  I'd start with the excessive current draw first as it is hard on the the expensive components, (power and output transformer along with the speaker field coil). 

Capacitor C41 would be connected to pin 4 of the 6F5. 

Looking at the schematic I have, that radio looks to have potential of receiving many stations and plenty of audio power.  A nice radio to have!

RCA / Re: RCA victor 1VF507
« on: January 18, 2019, 03:16:54 PM »
Thanks for the clarification on the RC1205 chassis.  I didn't realize there was that much of a difference between the 1205 and 1205C.  Another variation is mine doesn't have the AM-FM simulcast capability.  I don't have total grasp of the model numbering scheme, but my 3VF446 I believe was a 1963 model and the 1VF507 would put it in the 1961 area.  It makes sense that the RC1205 tuner would not have stereo FM, as I believe MPX was standardized in 1961-1962 time frame.  I learned something again today.  I'm curious, did your RC1205 have any connections for an outboard MPX decoder?

Thanks MM,

RCA / Re: RCA victor 1VF507
« on: January 17, 2019, 02:57:07 PM »
I have a 1963 RCA with the essentially the same tuner, 1205C vs 1205.  Your tuner is FM with MPX built in.  The selector switch should go from
FM STR-FM-AM-Phono-Tape.  The FM STR position is stereo FM.  The tuner and amplifier units are very nice and I'm very happy with the sound of my console.  You have P-P 6BQ5 outputs in it which gives you about 15 watts per channel. I bought my console for $25 and had several issues with it, but it's a solid performer, and once recapped has been trouble free.  One thing I noticed is the power transformer does run rather warm.  I repaired a friend's RCA which was a 1964 model but essentially the same chassis and amplifier and that transformer ran the same temp.  I think after a couple of hours it was around 150 degrees F, too hot to hold your fingers on it.

Chat / Re: Saving The Artist And His Skill
« on: December 25, 2018, 12:08:21 PM »
I just got back from staying at a friend's house.  He basically had emergency eye surgery on Christmas Eve and a follow up visit this morning.  This is the third time his retina detached in six months.  This time the surgery was different, he was awake during it all.  They had to remove some scar tissue on the retina and in order to "align" it he had to be awake.  You do know they pull your eyeball out of the socket to do surgery!!  He was describing the ordeal to me and how they pulled the fluid out and put in silicone oil in temporarily.  In 3 to 6 months they will pull the oil out and put the correct fluid back in, so he does have that to look forward to.  One thing he did tell me is this time he really has no pain in his eye, if there was some, a tylenol was enough to take the edge off.  Getting older does have some serious disadvantages.

It's just incredible what medicine can do nowadays!


Chat / Re: Merry Christmas
« on: December 25, 2018, 11:57:36 AM »
I'm late to the party, but I also want to wish everyone a happy holiday season, whatever it is.


Introductions / Re: A collaro f200c family hand down
« on: December 18, 2018, 10:21:44 AM »
Hello Marshall, I'm not a prolific poster, but I can tell you that you've come to the right forum.  The people here are very willing to help you out.  It's a wonderful crowd here.


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