Philco "Woodstock" 19" BW

[DavGoodlin]

This 1964 VHF-only set came from a fellow collector with some of the paper caps already replaced at the key spots, vertical section mostly.

After testing the Lo G2 CRT with my one tester, without a G2 setting, I was sure it was bad. Not so with a B&K tester set properly to Lo G2.

I finished the paper caps last night and was very impressed with the picture. But vertical is stretched in the middle and I haven't tried a 17JZ8 yet, sure I have a dozen of em.

The cabinet design looks like an early 60s Early American console style was compressed into a tabletop set for a very tiny apartment


IMG_5074

This set has all the plugs for an easily added UHF tuner, including antenna screws on the back cover.

The HV anode cap was cracked open, so I found a nice replacement and slipped it on.

This set does not use a voltage doubler, so B+ is 145 volts and the 4-section cap tested OK, so it stays.
There is an extra switch ganged with the power switch that disconnects the brightness control, so no bright dot when you turn it off. On the schematic from Electronic Technician Magazine, the clusterf-k vertical intergrator N3 is detailed.
No wonder restoring a Predicta is so component-intense, Philco went nutz with these.

Getting under some of these caps wasn't easy either. Just for good measure, Ill hit all the solder joints on the big tube sockets, they look iffy.
A bright light does wonders helping you see the traces from the top of the PCB, allowing yout to put the soldering pencil on the right spot.

[DavGoodlin]

On second thought, I wonder if this set even qualifies as "Mid century modern Eames atomic", common BS, due to over-the-top mini-colonial styling?
Odd looking? yes, but with a CRT that good, I just couldn't leave it sit in the barn.

I admit i got inspired by seeing all these mini-consoles

Im thinking of taking it to the DVHRC swap meet at Kutztown next week along with some other working 19" BW sets.

[VintagePC]

There is an extra switch ganged with the power switch that disconnects the brightness control,

Interesting approach, if I could find such a control for my own set I'd consider doing that modification. As it currently stands I just crank the brightness before power-off so that the dot "dissipates" quickly and doesn't do any gradual phosphor damage.

I could also see a failed switch there being the cause of many a serviceman headache for no picture on screen... IIRC other cathode-driven sets use a large-ish capacitor to B+ so it gets slammed hard DC negative on power-off and by the time it's discharged the emission has dropped enough that the dot is dim or completely gone.

[jstout66]

My '66 RCA B&W has that same switch set up. My switch was bad, and the service guy was like "wtf?".. He said the same thing.. that it was tied in to kill the brightness control, so no dot on turn-off. I lucked out as Moyers still had a few NOS switches on the shelf.
I like your set btw........

[DavGoodlin]

The 66 RCA probably has a lot of the same simplified circuits as BW sets became cheaper with color TV sales taking over. I also suspect Philco and RCA had swapped a few design people, being across the river.
That dot-kill switch makes me nervous. You have line voltage contacts up against contacts with DC.
Ok if if it lasted this long.

I replaced the across the line cap with an X2 rated safety cap.

I found 6 used 17JZ8 tubes in my stash. two were weak but a GE Compactron label improved the vertical somewhat.

[Electronic M]

Originally Posted by VintagePC

Interesting approach, if I could find such a control for my own set I'd consider doing that modification. As it currently stands I just crank the brightness before power-off so that the dot "dissipates" quickly and doesn't do any gradual phosphor damage.

I could also see a failed switch there being the cause of many a serviceman headache for no picture on screen... IIRC other cathode-driven sets use a large-ish capacitor to B+ so it gets slammed hard DC negative on power-off and by the time it's discharged the emission has dropped enough that the dot is dim or completely gone.

You could duplicate that design by making the brightness switch a relay with a 6 volt coil fed by the filament supply if it is a transformer powered set... Just remember if you can't get a 6VAC coil rely you will need to rectify the filaments for 6VDC.

[Don Lindsly]

That set is 450 ma series string. If the switch is not bad, it will probably last for another 40 years. The CRT beam current section carries virtually no current.

The RCA-Philco use of the CRT-power switch design was more driven by the control suppliers than engineer migration. There was not much creative engineering on B&W TV in the late 50s-early 60s. It was about cost control and avoiding warranty CRT replacements for burn spots.

[KentTeffeteller]

Interesting cabinet design. Funky console cabinet meets tabletop B&W chassis. I'd rescue and restore it for that alone. Very interesting set.

[old_coot88]

How long does the dot stay lit if you unplug the set? Just curious.

[DavGoodlin]

Originally Posted by old_coot88

How long does the dot stay lit if you unplug the set? Just curious.

I recapped this set, so I assume its operating normally upon power-down.
The raster shrinks to about postcard size before disappearing, so the anti-persistence switch is unnecessary?

On a side note, this set makes a nice picture but its moderately stretched in the middle and only slightly compressed at top and bottom when Hieght and Linearity are adjusted for a normal half inch of overscan.
I can probably blame the integrator K1, an RC network which shapes the vertical sawtooth. This is definetly has post-predicta improvements, and cost cuts as well.

[rca2000]

I am a bit surprised a set of this type would not be cold. How much more could a nice cold chassis cost anyway? We ALL kn ow they have a LOT of advantages..

I seem to recall my Grandparents having a set like this one (chassis-wise), until about 1980 or so. I TRIED to get that one--but my mom's family never were very kind about me getting old electronic things .."too dangerous', they always would claim..