Category Archives: On the Bench

BenchCam: Diagnostic & Repair on 1958 Admiral TV, Pt. 1

Advertisements

’50 Admiral Rebuild

Coming around toward the end of a full electronic restoration on this 1950 Admiral Model 22X26, featuring the 12″ 20Z1 chassis.

20160312_202718_HDR

Contrasting the technology with a selection from my Star Trek TNG VHS cassette library.

20160312_20274520160311_133127
Full capacitor compliment, resistors replaced where necessary, I.F. and sweep alignment performed. Original CRT is in great condition!

Zenith Porthole Wrapup

Well, we’ve finally come around to the final wrap-up on the Zenith Porthole “Aldrich” sent in by Richard G. from New Zealand. If you haven’t already, I hope you’ll also enjoy the first and second parts:

Part 1
Part 2

We received the cabinet back from Lance over at Nook n Cranny Refinishing much faster than expected, and as always, he did an immaculate job, so we were all set to reassemble as soon as we could wrap up the rest.

2 4

In the first picture: Here’s a shot of the first stage of the bezel refurb in-progress. That brassiness to the left is what was left of Zenith’s notoriously thin matte plating. I’m really not quite sure what this stuff is exactly. It looks like anodization, but as those in the plating biz will know, anodization is a process akin to plating that is done to aluminum in order to create that special matte finish. This bezel is essentially pot metal with a copper and nickel plating, followed by a topcoat of ‘whateverthisis.’ It’s so poor, it actually scratches off with your fingernail.

What I’ve done is taken the bezel to a high speed buffing wheel and compounded off that finish in one pass, and high polished the underlying nickel finish in the next pass. Perhaps not 100% authentic, but a huge improvement cosmetically!

Second pic: closeup of the ‘pencilbox’ (hidden control) area in dire need of new paint. The same paint runs around the inner and outer areas of the bezel as well- some of which had flaked off due to corrosion.

3 5

First picture: A shot of the entire bezel after buffing. The Zenith logo on the control door was also removed. The badge was painted, and afterward the top of each letter buffed off in order to bring out the polished nickel.

Second picture: A much needed and unexpected lightning storm. I enjoyed sitting under the eave out on the loading dock as the rain poured- there was just enough rain spatter blowing in to dampen the piece in order to wet-sand the painted area of the bezel to prep it for new paint. What a perfect day!

Next, we wrapped up the electronics. Here are some before and after shots of the underside of the main chassis:

zenith portholezenith porthole chassis restorationzenith portholezenith porthole chassis restoration

zenith portholezenith porthole chassis restoration

zenith portholezenith porthole chassis restoration

IMG_2242[1]zenith porthole chassis restoration

Every tubular capacitor and out of spec carbon resistor has been replaced. Every power resistor (those sandy pink pieces) have been replaced with a modern ceramic wirewound unit. Very important- because these things are prone to fail even if they are good due to internal corrosion. I never leave one to chance. Every electrolytic filter can has been disconnected and replaced with an equivalent unit underneath the chassis. I like to leave the disconnected units in place, since they are attached to the top of the chassis, they do show… so at least if they’re disconnected they can be left in place and not cause there to be a gaping hole. Purely cosmetic.

6 7 8 9 10

Chassis installed, ready to power…… Closeup of the freshly painted areas as well.

zenith porthole restorationzenith porthole restoration

This TV set has the honor of having a picture tube in EXTREMELY good condition. These TVs had screens that were, even when new, comparatively dim to later standards and were designed to be watched in a darkened room. This is one of the brightest pictures I’ve ever seen on a black and white roundie.

That’s it! We’re ready to crate up and ship.

’49 Sparton “Mirror-Lid” TV Resto

Prompted by one of my earlier posts “Sparton Mirror-Lid TV” a customer out of Grass Valley called and said that he’d found a similar model at a local thrift store… with all the knobs, everything in tact. How cool!

So today he brought the set in for restoration. He had already started on the cabinet, as he’s elected to do the cabinet work himself. We took the TV into the shop and I removed the electronics for him so he could take the cabinet back home to finish it up. Little details such as that right side handle hardware couldn’t be removed with the main chassis in place.

sparton mirror lid sparton mirror lid

I always check the condition of the picture tube before starting on, or quoting, a restoration. This tube checks about as good as a new tube! The rest of the chassis is bone stock, except for one bypass capacitor which was replaced- judging by the pink plastic body it looks like a 50s or early 60s era part. Other than that, several tubes had been replaced- and surely the picture tube as well, hence it’s good condition.

sparton mirror lid sparton mirror lid

Updates as we make progress!

Austrian 1957 Hornyphon TV Restoration

You might never see one of these again.

img_2245

A customer brought in this 1957 Hornyphon TV for a complete electronic rebuild. We will be going through and replacing every capacitor, resistor, diode, and any necessary tubes in this TV.

Hornyphon (or, Horny for short) was the Austrian division of Philips. The set adheres to the CCIR broadcast standard and runs off of 220VAC at 50Hz. We will be making no modifications to this TV whatsoever, which means that we will be restoring it to factory specification. The owner of this TV set lives here in Sacramento; a Physicist and ardent collector who wishes to maintain the originality of this extremely rare example of early European TV.

img_2247

So, a little bit about the story behind this set. As it was explained to me by the owner, this TV set was the very one in use in his family home in Austria when he was a child. Recently, it became necessary for him to clean up his family’s estate which this set was still a part of. He had it crated and couriered over from Austria to his home here in Sacramento. Aside from the set’s rarity and obvious collector value, it also maintains quite a bit of sentimental value.

So basically, we’re going to be rebuilding the electronics and returning everything to factory specification. The power supply and tuner are going to be kept original- not modified for US power, as the owner will be running the TV from a custom 220VAC 50Hz power supply which he built. The signals will also be fed into the TV using either PAL DVD or a custom CCIR signal converter

img_2246 img_2249

I have done an initial soft power up using a series combination variac and step-up transformer, which is detailed in the video below, and the set responded extremely well! Unfortunately the memory card on my camera ran out of room before I could generate a picture, but the CRT in this set is crisp and bright!

Zenith Porthole Update #2

Just posting a quick update on the status of Rich from New Zealand’s Zenith Porthole restoration.
zenith porthole IMG_2209IMG_2208[1]zenith porthole
Power supply block has been cleaned up and rebuilt. All capacitors replaced, both of the corroded high wattage sand covered resistors in the audio section and one small charred 1/2 watt resistor.

zenith porthole zenith porthole zenith porthole zenith porthole

The main chassis is undergoing complete rebuild. Everything is going well except for a bad volume control/power switch assembly. No direct replacements are available at this time so we might have to improvise this a tad!

IMG_2242[1]

Quick Repair on a very MOD 1975 RCA Portable TV

Toying around with some bench cam videos… check out this quick repair on a ’75 RCA from Hepcat Restorations which came in with no picture. I’m very happy with how this turned out and looking forward to making more!