Author Topic: 1964 Zenith console with drop-in tuner  (Read 2429 times)

electra225

  • Hero Member
  • *****
  • Posts: 1968
    • View Profile
Re: 1964 Zenith console with drop-in tuner
« Reply #15 on: June 13, 2018, 12:32:00 PM »
I know you've already considered this, Dave, but you might change the orientation of the cabinet with the internal twin-lead connected to see if there is any improvement.  Magnavox has that issue.  The internal antenna is extremely directional at times.  Even an external antenna will not help.  If it helps to change the orientation of the cabinet, then you can use an external antenna to advantage.
If it ain't broke, call me.  I can break it....

Motorola Minion

  • Hero Member
  • *****
  • Posts: 729
  • Southern Pennsylvania
    • View Profile
Re: 1964 Zenith console with drop-in tuner
« Reply #16 on: June 14, 2018, 11:52:07 AM »
I know you've already considered this, Dave, but you might change the orientation of the cabinet with the internal twin-lead connected to see if there is any improvement.  Magnavox has that issue.  The internal antenna is extremely directional at times.  Even an external antenna will not help.  If it helps to change the orientation of the cabinet, then you can use an external antenna to advantage.

The garage I'm working in has some odd reception quirks, with a big Pontiac 6 feet away, I definitely need an outdoor antenna. I have a dipole up at the ceiling but that seems only a bit better than a 30-inch clip lead I hang near the tuner. Even a 1966 Imperial chassis I'm working on has poor reception at the low end of the band, the only FM I'm interested in keeping on for more than a few minutes ::)

Putting the "shielded" cover back on the bottom of the chassis helps too. I'm not quite ready to drop it in the cabinet yet.

My 1960 Magnavox Symphony reception seemed odd this way too. This Magnavox had a 57-01 tuner having work done to it and a few new tubes. I could not get it right as it was "re-aligned" such that only the most powerful stations (commercial ones) came in clear. I suspect some one knew what they were doing generally but did not follow a few key rules like keeping shields in place and "maligned" it instead. :(

Luckily, I had a 57-03 tuner from a recent swap meet, complete and un-tinkered with. That one has not been aligned but the tuning cap's "copper fingers" are scratchy, and keeping from being all it can be. It has a very tight area below 90 Mc, but still can get a medium station next to a strong one.
Tubes - Magical - Tubes

Dave

Motorola Minion

  • Hero Member
  • *****
  • Posts: 729
  • Southern Pennsylvania
    • View Profile
Re: 1964 Zenith console with drop-in tuner
« Reply #17 on: June 14, 2018, 12:08:32 PM »
What is really holding this console back from sounding great is the 10 inch OEM Zenith speakers, 49-950. They seem worn out and one is especially fuzzy with a rubbing voice coil.

Sure I may be able to wet and realign the cones but in this case its better to upgrade them. I saw a post about an RCA (it was not Larry) having questionable woofer-driver speakers and the successful replacement of same with new ones for less than $50.

After looking on the website and comparing about 6 possible replacements, I found a speaker that is right in the 6-8 ohm impedance range AND 96 dB sensitivity . I ignore the power rating of 100 watts and look at everything else, sheet attached.

And, like the RCA owner did, I can enclose/isolate the speaker compartment on this model. Even with only a single-ended 6BQ5, sound and power could be comparable to a PP 6V6 amp. Even though its not one of the expensive Zeniths, I put effort into the chassis and want it to sound like one.8)

Tubes - Magical - Tubes

Dave

TC Chris

  • Hero Member
  • *****
  • Posts: 1173
    • View Profile
Re: 1964 Zenith console with drop-in tuner
« Reply #18 on: June 14, 2018, 11:27:37 PM »
Sounds like you're having fun.  I bought a couple 10" speakers to fill a Heath console and they are still sitting on the kitchen floor, awaiting time and opportunity.  It's summer now and there are summer things to do, so the electronics are deferred. 

But if you find time, post something about your rubbing voice coil repair method.  I've got a couple E-V reflex speaker enclosures built from kits long ago and using E-V LT-12 speakers, if memory is correct.  One developed a rub.  I added a shim under the basket and torqued the screws enough to make it stop, but that's a pretty crummy solution.

Chris Campbell

Motorola Minion

  • Hero Member
  • *****
  • Posts: 729
  • Southern Pennsylvania
    • View Profile
Re: 1964 Zenith console with drop-in tuner
« Reply #19 on: June 15, 2018, 08:41:53 AM »
I pulled the speaker out yesterday, the voice coil does NOT move freely. EIA code 343 was the OEM, and not their best work.

The cone is OK but the coil may have been, well cooked :o, causing all the friction. I swear I had a '68 solid state Zenith console with the same issue on the 10"drivers, I know those were baked 8) by a friend of mine, who showed its 2g record player and orange&yellow illuminated dials , ....when his parents were away.
Tubes - Magical - Tubes

Dave