Converting an FL1.6 to 50Hz? - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

3CX15000A7 · 27th Apr 2023, 5:57 pm

That's a good check!

I desoldered C2504 (disk capacitor) and I measured it. It said 367pf! (it should be 330pf)
I ordered two, so I measured the other, it said exactly 330pf.

Put it in and tried it. Same issues, maybe a little bit brighter.
Desoldering and measuring, it sad 354pF!

It seems these aren't stable, maybe the capacitance depends somewhat on the applied voltage . . .

What caps did you use for these ?

edit:
I checked the schematic again and something catched my eye. The original (blue) capacitor was a 330pF. But according to the schematic, it should be a 470pF for 28" ! All other revisions (AA, AB, AC and the FL1.10) seems to use 470pF for all screen sizes. Only the AD seems to differ for 21" using a 330pF (it's strangely not noted twice in the parts list, as usual as there are differences between screen sizes)

Maybe it was wrong all the time . . I am really sure it was a 330pF that was fit originally. Caps C2523 and C2524 all are: or 9.1/18 for 21' or 10/24 for larger sizes. On all revisions.

I will check my other FL1.0AD (a 25")

3CX15000A7 · 27th Apr 2023, 6:46 pm

My other fl1.0(AD) also has a 330pf cap at C2504

Could it be possible the HR should have a 470pf(and the original was designed for use with a 330pf)? If I am correct a higher value means lower EHT? Maybe the EHT is too high now, causing it to get out of it's normal regulation proporties .

3CX15000A7 · 30th Apr 2023, 10:12 pm

Meanwhile I checked the capacitors:

C2511, C2512, C2513 (around pin 8 of the line transformer)
C2510, C2519, C2520, C2521, C2523, C2524 around the deflection circuit

They all measured within a few percentage.
For C2504 (the disc capacitor) I tried a 470pf out of another tv and the original 330pf. (it measured ok . .) both gave the same issue. Picture size variation, both horizontal and vertical and poor focus (locally ! depending on the G2/focus setting more on 1/3 from top or 2/3 from top, both on the right side) by a bright screen.

Looking at the HR diemen schematic it says "pin 1 and 2 must be jumped." Does anyone nows what that means? Connecting these together will short out the HOT through S5510 . . I don't think that's what they mean . .

Maarten · 1st May 2023, 10:48 pm

It sure looks like the EHT is too low, not too high and it doesn't look like it's caused by one of the capacitors... I'll see if I can find out anything about the strange remark from HR Diemen.

3CX15000A7 · 2nd May 2023, 12:41 pm

thnx!

Theoratically, with the caps you can make the HV higher/lower, but don't influence the stiffness of the high voltage. Am I right about that? It looks like the EHT isn't stiff enough . .

I will scope the line stage when I receive a 100x probe, maybe something can be seen there . .

3CX15000A7 · 4th May 2023, 9:22 pm

I did some scope measurements around the HOT
What catched my eye is some kind of distortion in the pulses that gets worse when the brightness increases.

1 Base of HOT
2 Collector of HOT
3 emitter of HOT
4 junction between two dampers/junction c2523 and C2524
5 same point but closeup of the pulse /distortion

All are taken with a 30% white window as input, contrast around the point the beam limiter starts working.

Also, the peaks are all 10% high. At black screen they match with the service manual

3CX15000A7 · 11th May 2023, 7:00 pm

I found an original NOS Philips transformer and it seems that fixed the problem . .

Interesting, the picture was after fitting pretty much too large, looks like the HR did too much HV with dark pictures and too less with bright picture . . The picture after rough calibration is excellent

Maarten · 11th May 2023, 8:29 pm

Nice find, and a good warning that the HR replacement was indeed not a good fit for this chassis... Maybe for some other FL variant.

3CX15000A7 · 11th May 2023, 9:06 pm

Or maybe the HR was designed with a EHT cable with NTC in the EHT cable? There were chassis that used an NTC in the cable to stabelize the HV. The predecessor D16 mentioned this in the circuit discription.

Maybe such NTC is build in the original transformer but not in the HR. I didn't got an EHT cable with the HR

Btw I did find the transformer here:
https://www.eltradec.eu/index.php/de/w/vafb

They have a lot, including original Philips, Grundig, and some more. The fl1.0 transformer is very rare tough, I think they were very reliable and never be wanted that much as spare . .

27th Apr 2023, 5:57 pm	#21
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? That's a good check! I desoldered C2504 (disk capacitor) and I measured it. It said 367pf! (it should be 330pf) I ordered two, so I measured the other, it said exactly 330pf. Put it in and tried it. Same issues, maybe a little bit brighter. Desoldering and measuring, it sad 354pF! It seems these aren't stable, maybe the capacitance depends somewhat on the applied voltage . . . What caps did you use for these ? edit: I checked the schematic again and something catched my eye. The original (blue) capacitor was a 330pF. But according to the schematic, it should be a 470pF for 28" ! All other revisions (AA, AB, AC and the FL1.10) seems to use 470pF for all screen sizes. Only the AD seems to differ for 21" using a 330pF (it's strangely not noted twice in the parts list, as usual as there are differences between screen sizes) Maybe it was wrong all the time . . I am really sure it was a 330pF that was fit originally. Caps C2523 and C2524 all are: or 9.1/18 for 21' or 10/24 for larger sizes. On all revisions. I will check my other FL1.0AD (a 25") Attached Thumbnails Last edited by 3CX15000A7; 27th Apr 2023 at 6:24 pm.

27th Apr 2023, 6:46 pm	#22
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? My other fl1.0(AD) also has a 330pf cap at C2504 Could it be possible the HR should have a 470pf(and the original was designed for use with a 330pf)? If I am correct a higher value means lower EHT? Maybe the EHT is too high now, causing it to get out of it's normal regulation proporties . Attached Thumbnails

30th Apr 2023, 10:12 pm	#23
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? Meanwhile I checked the capacitors: C2511, C2512, C2513 (around pin 8 of the line transformer) C2510, C2519, C2520, C2521, C2523, C2524 around the deflection circuit They all measured within a few percentage. For C2504 (the disc capacitor) I tried a 470pf out of another tv and the original 330pf. (it measured ok . .) both gave the same issue. Picture size variation, both horizontal and vertical and poor focus (locally ! depending on the G2/focus setting more on 1/3 from top or 2/3 from top, both on the right side) by a bright screen. Looking at the HR diemen schematic it says "pin 1 and 2 must be jumped." Does anyone nows what that means? Connecting these together will short out the HOT through S5510 . . I don't think that's what they mean . .

1st May 2023, 10:48 pm	#24
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Converting an FL1.6 to 50Hz? It sure looks like the EHT is too low, not too high and it doesn't look like it's caused by one of the capacitors... I'll see if I can find out anything about the strange remark from HR Diemen.

2nd May 2023, 12:41 pm	#25
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? thnx! Theoratically, with the caps you can make the HV higher/lower, but don't influence the stiffness of the high voltage. Am I right about that? It looks like the EHT isn't stiff enough . . I will scope the line stage when I receive a 100x probe, maybe something can be seen there . .

4th May 2023, 9:22 pm	#26
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? I did some scope measurements around the HOT What catched my eye is some kind of distortion in the pulses that gets worse when the brightness increases. 1 Base of HOT 2 Collector of HOT 3 emitter of HOT 4 junction between two dampers/junction c2523 and C2524 5 same point but closeup of the pulse /distortion All are taken with a 30% white window as input, contrast around the point the beam limiter starts working. Also, the peaks are all 10% high. At black screen they match with the service manual Attached Thumbnails Last edited by 3CX15000A7; 4th May 2023 at 9:29 pm.

11th May 2023, 7:00 pm	#27
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? I found an original NOS Philips transformer and it seems that fixed the problem . . Interesting, the picture was after fitting pretty much too large, looks like the HR did too much HV with dark pictures and too less with bright picture . . The picture after rough calibration is excellent Attached Thumbnails

11th May 2023, 8:29 pm	#28
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Converting an FL1.6 to 50Hz? Nice find, and a good warning that the HR replacement was indeed not a good fit for this chassis... Maybe for some other FL variant.

11th May 2023, 9:06 pm	#29
3CX15000A7 Tetrode Join Date: Dec 2019 Location: Bergen op Zoom, Netherlands Posts: 65	Re: Converting an FL1.6 to 50Hz? Or maybe the HR was designed with a EHT cable with NTC in the EHT cable? There were chassis that used an NTC in the cable to stabelize the HV. The predecessor D16 mentioned this in the circuit discription. Maybe such NTC is build in the original transformer but not in the HR. I didn't got an EHT cable with the HR Btw I did find the transformer here: https://www.eltradec.eu/index.php/de/w/vafb They have a lot, including original Philips, Grundig, and some more. The fl1.0 transformer is very rare tough, I think they were very reliable and never be wanted that much as spare . . Last edited by 3CX15000A7; 11th May 2023 at 9:31 pm.