Crawls Backward (When Alarmed)

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Zenith H845Y Radio Overview and Chassis Removal

A bit of a change from guitars and amps on this project.

I have a whole slew of vintage radios.  Quite a few are restored, but I also have quite a few in the project queue, but they keep getting spurned!  Here's one that shouldn't take much effort.

It's a 1964 Zenith H845Y.  This is a large 8-tube tabletop AM-FM set, featuring a 7 inch woofer and a 3 inch tweeter.   These radios have a reputation for outstanding performance and fine tone quality.

There were 4 variants of this radio - the H845E, L, W, and Y.  They all share the same chassis (Zenith's number for the chassis is 8H20), but have different cabinets.

I think it's a relatively attractive radio.  Some 60s radios are pretty ugly, but this one isn't bad.  And it's in excellent cosmetic condition. 

That vertical dial was seen on a lot of Zenith sets from the 60s into the 70s.

And of course, this is one of the last tube sets Zenith made.  Its lineage goes back to the late 1940s with the well-known bakelite AM-FM sets.  The circuits on all of these Zeniths are more or less identical.


This one plays very well, but has noticeable power supply hum.  I'm going to recap it and align it.

First thing is to take off the back panel.

It's straightforward - there are four 1/4 inch screws holding it on.

Before we can fully remove the panel, we have to unsolder the antenna leads.

You can see how I labelled the leads for future reassembly.  I like to use solder wick to get all the old solder off - this way I'll be soldering to a clean connection later.

Then we take off the four 5/16 inch screws on the bottom holding the chassis to the cabinet.

I didn't photograph the next step - which is to remove the control knobs from the front.  They just pull off their shafts.

Then we can disconnect the speaker wiring.  The speakers are attached to the cabinet, so we just slip the connectors off and slide the chassis out.

Here's the chassis removed from the cabinet.  You can see that 7 inch (about 18 cm) woofer - this is a good-sized radio.

Here's the chassis from the front.   You can see it's super clean and unmolested.

The red arrow points to the Mallory FP filter capacitor can.  I'll be removing and restuffing it with modern Panasonic capacitors.

The blue arrow points to the selenium rectifier.  I'm going to bypass that with a modern silicon 1N4007 diode.  The selenium rectifiers have a reputation for going bad, so I always remove them from the circuit.

I will leave the selenium on for looks - no reason to remove it. 

This radio has never been serviced.  I like 'em this way.

Not only that, all of the tubes are the original Zenith-labelled ones.  It's relatively rare to find a set with all original tubes.  

 
 
 
 

Post a Comment 4 comments:

  • Unknown said...
    February 11, 2017 at 4:04 PM
    Would you post a parts list as I have the same radio and would like to use your blog as a walkthrough? You could also email at kelsoklein@gmail.com
  • Unknown said...
    February 11, 2017 at 4:04 PM
    Would you post a parts list as I have the same radio and would like to use your blog as a walkthrough? You could also email at kelsoklein@gmail.com
  • Kelso said...
    February 12, 2017 at 7:58 PM
    Please do. I am losing am and fm. When I turn it on I have no volume control until it decides to work properly then I get random hisses and pops. It hums too
  • Kelso said...
    February 12, 2017 at 8:15 PM
    This comment has been removed by the author.

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