1956 Zenith Hairpin Leg Consolette HFY-17E

[Hi-Fi-Mogul]

This little lady was dropped off on Sunday.

She is one model I've never seen posted anywhere,
and from looking at the schematic, it will be
a straightforward re-cap.

Please cross your fingers for me that the electrostatic
speakers work.

The Cobramatic Stroboscope is the later model with
a ceramic plug-in pickup.
I haven't worked on a true Cobramatic in years, so
this will be a refresher course for me.

I won't start on it for a while, but I'll post once I
get going.

[William]

That's cool looking and I have always had a thing for Blonde. I have never seen the REAL Cobramatic in person, the only one's I'm familiar with are the VM Cobramatic's. It looks like the top suffers from the same issues as most of my finds.

Bill

[Hi-Fi-Mogul]

Hi Bill,
I came up with a simple fix for the top of the lid.

I will strip only the top surface, and the owner will
then paint it an appropriate gold/blonde tone.

Should be nice, as the rest of the cabinet appears to
just have the usual grime on its finish.

[William]

My one item that needs the top fixed is blonde but in a faux finish. Not sure what to do with that, and like yours the rest of the cabinet is fine. My other stuff is either Mahogany, Walnut, or Cherry. They all need the tops worked on, and the rest of the cabinet are fine. I keep waiting for a brainstorm idea that will let me preserve the sides and be able to match the top. So far, the brain is failing me.

Bill

[electra225]

Never have seen one like that one. Would you fill us in on your routine for repairing a blonde finish? One of the guys on the big forum redid a blonde cabinet one time, years back, and it looked amazing. I can't find the post anymore. It may have been 15 years ago. I don't see the oscillator circuit, so maybe no Radionic cartridge, so what cartridge does it have? What are the pitfalls on a Cobra changer? Didn't we have a conversation awhile back on how to replace those electronic tweeters with a regular cone speaker?

[Hi-Fi-Mogul]

Greg,
As I posted earlier:

1. I'm going to strip the finish off only
the top surface of the lid.
Take it off down to wood using an
environmentally friendly stripper I found some
years ago. Cannot remember the name now,
but it worked wonders.

The owner said she would then carefully paint
the top lid surface with a complementary color.

2. This Cobramatic has a plug-in ceramic pick-up.
Since this existed prior to stereo, there are no 0.7 mil
stylus carts, only 1 mil stylus.
I've seen a video where someone installed a new
Pfanstiehl cart, but they gave no info on how it was done.

Yes, we discussed the possibility of using a regular
tweeter, after d/c'ing the high voltage connections
on the electrostatic tweeters.

One pitfall of these Cobramatics is obtaining the
accurate RPM when a particular record speed stop
is selected, due the design of the idler and
drive wheel system.

From reading the nice Stroboscope manual in Beitman's 1953,
you can make adjustments to home in on the correct
RPM to match it on the speed stop of the escutcheon.
You use a strobe disc in the process.

[Hi-Fi-Mogul]

Made some progress on the cabinet.

I did a soap and water sponge cleaning that removed
plenty of dirt safely.
The over-all finish looks good.

I removed the damaged top lid, taped it off, and
applied Back to Nature paint stripper.

The brass finish hairpin legs had copious amounts
of oxidation.
I had a serendipitous expierience.

I found a piece of 0000 steel wool in a plastic bag that I had used
to apply Howards Restor-A-Finish on a previous project.

As I worked on the legs with that wool, they rejuvenated really well.
There was some of the finish product left in the wool,
and it somehow interacted well with removing the
oxidation.

The amp chassis is mounted using 2 pieces of wood.

The chassis ground leads from the electro-static speakers
connect with a clip to the edge of the chassis.

There is a lot of oxidation on those clips and scant
room b/t them, the chassis leading edge, and the
wood mounting piece to slide them off.

I applied 2 drops of Supco rust treatment, and
will let it sit for a day.
Then I'll figure out what to try to dis-assemble first, so
as not to break those ground lead clips off their wires.

The HV e-static speaker leads from the amp use tube shaped connectors,
and should be easy to remove.
They were hidden under that piece of greenish paper,
which is tough as leather it seems.

[electra225]

Your progress is looking good, Mr. Mogul. Good luck with the speaker connections. Little record players can be as much work as a Concert Grand......

[William]

It's looking good Mr. Mogul. I see your tweeters are red. I worked on a Zenith that had blue tweeters. I wonder if color was significant to the frequencies/crossover of the tweeters?

Bill

[Hi-Fi-Mogul]

It's looking good Mr. Mogul. I see your tweeters are red. I worked on a Zenith that had blue tweeters. I wonder if color was significant to the frequencies/crossover of the tweeters?
Bill

Bill, I had that same question, as I'd seen small suitcase
Zeniths with different colored e-static speakers, also.

[William]

It must have something had something to do with that, or they outsourced them, and different companies used different colors. Maybe someone on the forum has the answer.

Bill

[Hi-Fi-Mogul]

I stripped the damaged finish on the top of the Zenith's cabinet lid.
It took 2 applications, but it came out clean and
down to wood.

The owner picked the lid up for painting it a complementary
solid color to match the original finish.

Today I was able to remove the e-static speaker ground
wires clipped onto the chassis, w/o any wire damage.
The positive wires of the e-statics were simple to remove.

Woofer speaker wires disconnected easily.

A pilot light mount was in a very tight spot
to remove, but it came off OK.

Now I can remove the amplifier easily.

Next I'll start checking the trannys, tubes, and
so forth.

[electra225]

I wonder if the blue speakers are specific to a certain manufacturer. Sometimes, these seemingly simple record players can be a pain to get apart. Continued good luck with this project.

[Hi-Fi-Mogul]

1. Tubes all check out good.

2. I've been checking continuity on the PT and OPT.

I am confused by the difference between the Beitman schematic
and the Sams.

Please view each schematic's power supply section and tell
me if there are 2 different conventions being used there
on the secondary windings diagrams of the power transformer.

3.I also had a time figuring where to put a jumper wire on
the phono motor socket to complete that side of the
primary, so I could test continuity and resistance.

[electra225]

I think both circuits do the same thing, essentially. They are drawn differently. The confusing part for me is the differences in voltage specs. Sams give output tube plate voltage as 250 volts. The other one gives the spec as 243 volts. Not that big of a difference, but I can see where that might cause confusion. Certain components are shown in different locations between the two drawings. They are in the same circuit, just drawn differently. Are you having an issue you are troubleshooting with this project?

[Hi-Fi-Mogul]

Greg,
I was really confused on viewing the 120 VAC supply
written as connected to the secondary winding of
the power transformer in the Beitman schematic.

It's shown coming off the 120 VAC phono motor socket
connector.

That didn't seem possible to me.

[electra225]

The Beitman's drawing of the power transformer is a mirror image of the Sams drawing. The phono motor is in the primary of the PT just like it is in the Sams. Beitman's has drawn the primary on the other side of the page. Look where they have drawn the power plug. It is to the left of the transformer in Sams, to the right of the transformer in Beitman's. Beitman's shows a four-pin phono plug, Sams shows a three-pin plug. I'm guessing the plug has four pins, but only three are used. I hope this helps...

One thing I noticed that doesn't make sense to me. The legend says the phono motor is 117 volts AC, but draws its supply in half the primary. Then they draw the 6.3 volt filament tap in the primary of the PT. That is probably wrong. They have drawn the PT backwards. That IS confusing. I'd say that is a mistake of some kind, either when they drew it and proofread it, or when they printed it. The primary of the PT is shown as the secondary and vice versa. Sans is known to have drawn things wrong, particularly in TV drawings. I'd suggest using the Sams drawing in this case and disregarding the Beitman's. I believe they have the wiring right, but the confusion on the PT drawing is discouraging.

[TC Chris]

I am confused by the difference between the Beitman schematic
and the Sams.

Please view each schematic's power supply section and tell
me if there are 2 different conventions being used there
on the secondary windings diagrams of the power transformer.

Yes. The Beitmann's/Zenith version is confusing because we are used to seeing the primary on one side, secondaries on the other, as on the Sam's version. I love the clarity that Sam's brought to the circuit diagrams.

Chris Campbell

[Hi-Fi-Mogul]

Thank you both for seeing what I saw there.

I am using the Beitman's for only wire color clarification
on that AC phono motor plug, which does only have
3 connections/wires.
Beitmans gives the wire colors of that motor plug,
while Sams does not.

One other item, while we're here.

I concluded that I needed to jumper the phono
motor plug b/t the Bl(ue) pin 4 and Blk pin 2 wires,
so I would have a connection to check the
primary for continuity.

I did get "proper" Ohms reading and a continuity buzz
from my DMM.

Did I do that connection procedure correctly ?

The meter probes in the photo are not in the
test placement, I just wanted a photo for you all.

[electra225]

Pin 1 is power line to one side of PT primary
Pin 2 is one side of the power line to phono motor and other half of PT primary.
Pin 3 is unused.
Pin 4 other side of the line with safety cap to chassis. The switch on the changer will close this connection to supply power to the amp.

You would jumper pins 1 and 4 to run the amp with no phono motor.
You would check pins 1 and 2 to check primary of PT. I believe what you were measuring was resistance from one side of the power plug to chassis thru the safety cap.

Hope this helps, Mr. Mogul....