3/27/2014

Admiral Y6071 9L2 Console

So a guy I used to work with approached me shortly after I started working at my job when he found out I worked on old radios, and he inquired about a console he owned that had been in his wife's family. He was looking to sell it and was wondering if it was worth the $100 he was hoping to get out of it. I explained all the vagaries of mid century consoles and how much they might be worth and why.
 
 
 
After several days I finally got him to get me pictures of it. It is a plane Jane el cheapo Admiral and after seeing it I told him if it worked it might be worth maybe $50.

Well step forward several months and his wife was tired of it taking up room in their house, so he approached me again asking if I wanted it I could have it for free. I told him I would give him $25. We picked it up and brought it home. I found out that it is not as big as I thought, It is long, but it is only about 3 feet high and maybe 2 feet deep. I am not sure where he got the idea that it was working as someone had cut all the wires to the speakers and the interlock. This happened a long time ago, because some of the wires had green goo leaking out of them. It looked like someone had tried to Jerry rig the console to play from an external source to the speakers.
 
 
 
 
 The Record player looked to be in good condition, and has a sharp needle in it.
 
 
I at first thought that If I did not get it working in the console, I could maybe mount the chassis in a home made box, and install an isolation transformer. When I downloaded the Sam's for it, I found that the output transformers are for a 1.4 ohm load. The tweeters and woofers are listed as 3-4 ohm in Sam's, in the picture it looks like the tweeters are in series and then in parallel with the woofer. So unless I wanted to use this Chassis with only the speakers from the console. I would probably need to replace the output transformers. Since this thing has stereo single ended 45b5's I doubt it puts out more than maybe 5 watts

The chassis was held in by only 3 screws, I blew off about 50 years of dust. I think it was made in 1964.
 
I tested all the tubes with me Eico 625, The only tube that is questionable was the 19EA8. Not sure if it is bad or my tester doesn't test it right, or what exactly. It measured Weak in both tests.

I checked over the circuit board and did not see any obvious defects. It took about 3 tries to identify the correct wires to input power (dim bulb testers are a life saver), as the wiring is cramped under chassis. I Identified the Proper speaker connections and hooked them up to my bench speakers.

I powered it up on AM and it worked, I scanned the AM band quickly and everything is good there. I switched over to FM and did the same thing (all good). FM Stereo on the other hand is muddled, and the stereo light does not come on (I have not checked if it is good). There was NO hum on any band. I changed out my Dim Bulb for an amp meter and got around .3 amps reading.

I rebuilt the power supply and replaced a cracked resistor circled in green on the right. I replaced several other capacitors on the main board.
I needed a replacement stereo indicator bulb GE 49. The problem is "Radio" shack does not carry them. There is a local place here called Lighting Unlimited, but my experience on old style bulbs is that they are more like "Lighting Limited".

The it struck me. This thing puts out 2 volts, 2 volts DC.... Hmmm, let me think. LED. AH HA!

I took the old bulb, broke the glass, de-soldered the bulb and melted out the epoxy or whatever holds the bulb in. I Soldered in it's place an old red LED I had. It works perfectly and unless there is some kind of power surge, will probably last forever.
 
 I also did a complete AM and FM alignment. Reception improved some, but stereo was still messed up. With some suggestion from a forum I fed a 19KHz signal directly to the input of the stereo decoder section, by doing that I was able to complete the Stereo alignment.

When I later got a Leader LSG 231 FM stereo signal generator, I was only able to improve the FM stereo alignment slightly better.

At some point I need to refurbish the Record player and then decide what to do with the cabinet.

2/10/2014

Silvertone 7407 Refurbish

Picked up this Silvertone from an Antique store for $20 not working. The receiver chassis number is 528.54746 and the Amplifier is 528.69240 There is a number stamped on the amp chassis 30-125-2 or it might be 30-125-2a.
 It was plugged in and probably in use at one time at the antique store.

All it is, is a Silvertone Console Tuner, and amp Chassis inside a table top cabinet.
It appears to be all original inside.

It was in need of a recap.

This is the Schematic of my amp as found.

It has dual station dials, and indicator lights for being on station (in Mono),
 And in Stereo.

I had to replace:
1 - 6be6
1 - em84 with a NOS one from ebay.
2 - 6bq5
The resistor on the em84 eyetube.
all the electrolytics
several resistors on the right channel of the amp (the left all measured good).
There was 1 burned and split resistor in the tuner, and one singed resistor in the power supply.
I blew up a 100uf e-cap in the voltage doubler and had to replace that with a much higher voltage rated one. Seems that the amp originally had a 200vdc cap in the voltage doubler circuit. Why mine blew I do not know. The replacement 450vdc cap works fine. It has a Phono and Tape in. I have a CD player or mp3 player on the Tape In.
For $20+$45 in parts to fix, you can't get much better than that. It sounds really good through my Fisher XP-9C Speakers.

1/20/2014

Recent Acquisitions

Eico 369 Sweep Generator


 Did a full recap and calibration

Lloyd's TM-838n 2 speaker radio.

 
 


 I installed an isolation transformer and a fuse.

Lambda LP-532-FM Calibrated DC power supply





12/28/2013

Archer StereoDyne/3 Amplifier Clone

I was interested in building a small single ended amplifier, and found several that had been sold in the 60's. They went for quite a bit on ebay and I figured I would build one.

The amp in question was sold under several names and may have all used the same or similar design. The amps were sold under these names:
Archer StereoDyne/3
Truetest stereo/8
Monarch SA-10

I found this in an online copy of a Radio Shack Catalog.
I had found a stainless steel drawer at Goodwill. I had to order a couple of Edcor XSE15-8-2.5K audio output transformers, which took 6 weeks to ship. I had most of the other parts and only had to order some POT's and 3 meg resistors.

I designed the Layout of the amp in Autocad 2002. I then printed the drawings at 1:1 and taped them to the drawer.

 Center punched and drilled the holes.

Attached all the hardware, switches and pots.



 Then soldered in all the components.
There was some problems with hum and it took a couple of days to troubleshoot with help from an Antique Radio Forum.This is the original Schematic.
Here is the Final Schematic.
These are the pics of the finished amp. It still needs labels and better knobs.

Changes from the original design:
Added Isolation power Transformer to prevent accidental electrocution.
Better Audio output transformers.
Power indicator light.
3 prong plug grounded to chassis.
2 Channel input.
Fuses on input and output side of power transformer.
Used shielded cable for all the input wiring up to the 12ax7.
Added a 100uf Capacitor after first filter to reduce ripple by half.
Added a 22uf capacitor off of 125v source to pin 1 of both 35c5's to cancel out hum.
Removed "tone control".
Removed Stereo/Mono switch.

Hum is now down to 20 millivolts and can only be heard with your ears about 6 inches from the speakers.

This is a 1.5 watt per channel max, single ended tube amplifier. It will drive most any speakers just fine, frequency response is approximately 70 to 17000hz Not Hi-Fi, but 99% of the population can't tell. It will not do much in the way of deep bass, but bass is over-rated anyways.

12/26/2013

No Fuss "Lasagna"

Prep time 30 minutes.
Bake time 30 to 45 minutes or until cheese on top starts to brown.


Ingredients
1 - pound Italian sausage
1 - onion chapped
2 - cloves garlic chopped
1 - 12 oz bag egg noodles
2 - small cans mushrooms (or 2 cups fresh sliced)
16oz - Ricotta
2 - eggs
Italian Seasoning
Salt
Pepper
2 tablespoons butter (not margarine YA PANZY!)
2 - 32 ounce jars spaghetti sauce (your choice)
1 pound mozzarella cheese grated.

Heat Oven to 350 degrees.


To cut recipe in half , use half the noodles, and 1 jar spaghetti sauce.

Boil noodles 4 minutes (you read that right).

Don't worry about exact measurements or amounts, feel free to skimp on ingredients that you think are bad for you (or you don't like), but don't blame me if it doesn't turn out good (WUSS!).

Cook chopped onions in butter with 1 tsp salt, and 1 tsp pepper until slightly translucent. Brown Italian Sausage with 1 tsp Italian Seasoning, 1 clove garlic, add mushrooms towards the end.

While browning sausage, add 1 chopped clove garlic, 2 eggs, and 1 tsp Italian seasoning to Ricotta cheese. Whisk together.

Drain noodles, add (everything) both jars spaghetti sauce, sausage, onions, mushrooms, and ricotta cheese mixture to large pot and mix together carefully.

Dump in to one large lasagna pan or 2 or 3 9x13 inch pans. Top with grated mozzarella, and bake as noted above.

Remove from oven and let cool 15 minutes.

12/11/2013

Knight Signal Tracer

Picked this up at hamfest Saturday for $15. it does not have the probe and I will be making one.

Before




I did a simple recap on it, which reduced the noise levels on the (non noise setting). I replaced the cord, mic connector, and added a fuse. I removed the nasty stained speaker grill and replaced it with some black speaker cloth and a box fan guard. I then gave it a lite bath.

The 6E5 Eye tube seems a little dim and I will look for a replacement at some point.

After

11/24/2013

General Electric Super Radio I

Never much cared for AM/FM only Transistor Radios, especially boring GE's. I had read many time on several forums about the GE Super radios. Today I found one at Goodwill. A Model 7-2880B Which is one of the first models. Many people claim it is very sensitive and a good performer, but I am often skeptical. My test of any of these claims is how well they can receive KAZG. KAZG is a Daytime only station that drops to 50 watts at night. I plugged this radio in, at the store which was about 12 miles from KAZG and it was after sunset. Normally any radio I try, will pick up either nothing or just barely get a signal. This radio has promise because it was staticy but listenable. The final test is when I get home. My house is about 4 or 5 miles from the transmitter. After sunset the station is very staticy with most radios. With this Radio the station sounds almost as loud and clear as most other radios do in the daytime (for the same station). It even beats my Zenith Royal 780 The top contender of the portable radios I own.
 The large speaker and tone controls are a plus as well.

I tested it one night and I was able to pick up KNX 1070 LA 372 miles from me, and KKOB 770 in Albuquerque, NM 338 miles from me.

11/17/2013

Refreshing The Fisher XP-9C Speakers Part III

Finally got a chance to work on these speakers again. I made a new frame for the speaker fabric. I was able to re-use the old fabric as it had not shrunk too much.
The picture below shows the frame under the covering because of the camera flash but it is not visible otherwise.
There is one final issue. one of the speakers has a problem with the "Fried egg" tweeters, they do not work unless pressure is applied to a specific point on their rims. I have them temporarily working with a pair of magnets. I will have to replace all of them at some point.

How do they sound? Great but, Very BASSY. Treble needs to be bumped a bit to compensate. I tested them with different records and CD's. They really like orchestral music. But sound good with Rock. They did not work well with my Beat Dominator CD. The bass was just a little too low for the crossovers. If I kept the volume at a reasonable level they could handle it, but turn it up too much and they cut out.