Rare find! A Magnavox Brittany tv!

[Yamamaya42]

Originally Posted by Electronic M

I most cases where a 1000pF or higher Mica is used you can get away with a standard film capacitor... which is what I usually do.

I do have some cheapy generic film to replace that 4700pf if needed, but as the v-lock seems stable now, most likely won't need it.

the new 100pf will come today, removed the old one across the variable capacitor, it's testing at 152pf, i'ts prob leaky like the other one was.

[Yamamaya42]

Confirmed, the 100pf cap across the variable capacitor, is leaky as the other one was testing via the same way before, +35v hooked to one end, the other to negative via 1m resistor pull down, if good/ no leakage, there should be no voltage seen across the resistor, but as before, saw about 25v, this is no doubt the source of the unstable lock in the horizontal oscillator in the same way the other one caused trouble in the vertical.

Odd though, that of the few mica caps replaced, the only 2 that seemed to be leaky were both 100pf and same type, coincidence?

[Yamamaya42]

so far so good.

http://suzaku.live-evil.org/0702252158.mp4


seems mostly stable, no wax loss yet on this FBT.
no smoke or fire!

[Yamamaya42]

http://suzaku.live-evil.org/0703252258.jpg

the rust cleaned off the focus coil very well with WD40, and replacement cap for the yoke seems to be a pure and natural fit!

[Yamamaya42]

First test of the 16LP4 was a success!

http://suzaku.live-evil.org/0708251931d.jpg
http://suzaku.live-evil.org/0708251931.jpg
http://suzaku.live-evil.org/0708251931b.jpg

The Ion trap works, brightness works, it did not with the test CRT, smearing is gone, I may have to add a resistor in parallel with the focus coil, as I don't have the full range i should, but I expected that as the lp4 has a weaker gauss than the other tubes, but this is a big step forward!

[Yamamaya42]

I was sort of expecting to see this with the 16LP4 as mentioned it needs a less magnetic field to focus than the 16FP4 that was in there.
16FP4 = 146 ma
16LP4 = 110 ma
http://suzaku.live-evil.org/focusa.jpg

The pics posted were taken with R209 set to minimum, but the field was still too strong, the entire sets positive bias is being shunted trough the focus coil, via the 2 centering pots (H/V), far end hooked to the main bias pi filter, which is then passed on to the bleeder network after the focus coil. (250v)

To try to get the needed range, I could change the value of R209, but that will put even more stress on R210, or what I will more likely do is put a shunt resistor across the focus coil like seen in the RCA 630TS to lower the field power a bit, 1.5k-2k or so.

[Yamamaya42]

First test fit of the NOS 16LP4 in the cabinet.
http://suzaku.live-evil.org/0711252004a.jpg

http://suzaku.live-evil.org/0711252004.jpg
As I thought, I will have to shift the yoke wooden mount back a bit to get it to work, no biggie.

The front glass is not perfect, but at least it's not broken!

[Yamamaya42]

It now fits!

http://suzaku.live-evil.org/0712251351a.jpg

you can see how far I had to shift it back to fit the larger size of the bell on the 16LP4.
http://suzaku.live-evil.org/0712251352a.jpg front.

[Yamamaya42]

A test of the CRT mounted in the cabinet, using the OEM speaker.

http://suzaku.live-evil.org/0715252030.mp4

Ion trap is adjusted correctly now.

I tried a 1w 1.2k resistor in parallel with the focus coil, did not last long burned up fast. will try a 2k 5-10w later.

still have to adjust screen geometry and stuff once all is said and done.

[Yamamaya42]

So far so good.
The flyback transformer holding up well, no a drop of wax at all, no idea why the other one fried.

pic is a bit wide, bit i may be able to adjust it down horizontal linearity is also a bit off, not tried to adjust it yet, but over all it's pretty good.

[Yamamaya42]

http://suzaku.live-evil.org/magie-mica.jpg

again, re-using an older pic-post.

got a question on how the width coil works. which can be switched in or out on this set, have not tried to adjust it yet, it is broken but can still be tweaked, does it make it wider, or more narrow when engaged? i need it to be more narrow! L133, the pic it a bit too wide!

also I have found that adding a 900k resistor in parallel to the focus coil gets me good focus range!

[Yamamaya42]

I ordered a new width coil, merit mwc-8, cheap $10.

Which will hopefully get the screen to shrink and fit a bit better, the original has a broken paper tube and is hard to adjust.

Once width is set,I can try to adjust horizontal linearity, which is a bit off as well.

And What's up with the "server busy" errors that are popping up so much lately? Annoying!

[timmy]

Width coil only gives about a half inch Maybe less.

[timmy]

Originally Posted by Yamamaya42

A test of the CRT mounted in the cabinet, using the OEM speaker.

http://suzaku.live-evil.org/0715252030.mp4

Ion trap is adjusted correctly now.

I tried a 1w 1.2k resistor in parallel with the focus coil, did not last long burned up fast. will try a 2k 5-10w later.

still have to adjust screen geometry and stuff once all is said and done.

This pic shows horizontal drive a bit high with the white line down the center.

[Yamamaya42]

Originally Posted by timmy

This pic shows horizontal drive a bit high with the white line down the center.

no horizontal drive adjustment on this chassis, just width and linearity.