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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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28th May 2017, 8:44 pm | #1 |
Pentode
Join Date: Oct 2016
Location: Ware, Herts, UK
Posts: 169
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Philips V2000 - 2nd Generation Video Head compatibility
Hi all,
I was asked a question today which I couldn't answer - maybe someone on here knows. I have a Philips VR2324 (Video 2000) machine which either has failing heads or perhaps the brush-contacts to the head drum. Anyway, someone I know has a VR2340 and a 21VR20/22VR20 and we wondered whether the heads would be transplant-able into my VR2324. Any ideas? I've been told the upper head drum was a pig to re-align after removal - is this true? Any tips? Thanks Rob |
28th May 2017, 11:01 pm | #2 |
Octode
Join Date: Jul 2004
Location: Evesham, Worcestershire, UK.
Posts: 1,415
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Without the special plastic drum carrier and the two plastic shims replacement of the head drum on these machines is difficult as they accomplish two vital tasks, namely setting the head drum position correctly relative to the motor shaft position plus setting the air gap between upper and lower drum correctly, as to whether the parts are physically compatible i'm not sure if they are exactly the same.
greg. |
29th May 2017, 1:33 pm | #3 |
Pentode
Join Date: Oct 2016
Location: Ware, Herts, UK
Posts: 169
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Thanks Greg. I think I'll hold on for a VR2324 junker, then see if I can replace the entire video and cassette loading component over. (The power board was recently serviced for me - new caps etc, but the heads appeared to be dead).
Regarding the upper drum replacement - is there any advice for setting the air gap correctly - or is it "keep securing it in different positions until the picture is clear of noise" ? Rob. |
29th May 2017, 9:49 pm | #4 |
Octode
Join Date: Jul 2004
Location: Evesham, Worcestershire, UK.
Posts: 1,415
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Hi rob,
the plastic shims set the air gap, it was really simple you dropped the drum onto the shaft with the shims in position and then tightened the lock screw after which the shims could be pulled out and the drum retainer removed, they were really plentiful because every new drum came equiped with a set of shims and retainer, but that was thirty odd years ago, it's possible someone on this forum may still have such items they could lend you. regret i'm unsure about the shim thickness, they were very thin, just a few thou. hope that info helps. greg. |
30th May 2017, 9:32 pm | #5 |
Heptode
Join Date: Feb 2014
Location: Nottingham, UK.
Posts: 645
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Hi,
Only ever did a head swap the once on these, and the drum came from Philips without the mylar spacer shims! At the time Philips were making VHS drums with a similar mounting arrangement, apparently you can use these shims for the V2000(as told by Philips TLO). So if anyone has an NOS head drum for a later Philips VHS (original turbo deck) you can use these for upper/lower drum spacing. Unless you really have to, I wouldn't split the upper/lower drum. SJM. |
5th Jun 2017, 8:57 am | #6 |
Pentode
Join Date: Oct 2016
Location: Ware, Herts, UK
Posts: 169
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Thanks Guys. All good advice. As I don't have access to the spacer shims, looks like a simple upper-head-drum swap out isn't on the cards for me.
Will look out for the VHS NOS head adverts incase they include some. |
5th Jun 2017, 1:29 pm | #7 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,184
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Re: Philips V2000 - 2nd Generation Video Head compatibility
It should be possible to use a sheet of paper as a shim, but I'm not sure which weight it should be. The thickness of the shim is probably documented somewhere.
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5th Jun 2017, 3:13 pm | #8 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,884
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Re: Philips V2000 - 2nd Generation Video Head compatibility
I imagine two pieces of card would do but the thickness is critical.
Don't you also need the red plastic cover that aligns the upper and lower drum? I know you did with the VHS versions. I remember buying a top of the range turbo deck for very little money when they were almost new from an ex-rental outlet. They thought there was a serious problem when in fact the heads were misaligned. Glyn |
6th Jun 2017, 3:21 am | #9 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,184
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Re: Philips V2000 - 2nd Generation Video Head compatibility
The cover isn't needed, but later VHS models used a pin for the position alignment. Earlier VHS models didn't. I'm not sure about VCC.
The thickness might not be _that_ critical as I know someone (a former car mechanic who tinkered a bit with videorecorders when they were still in demand second hand) who used to swap VHS drums by just eyeballing the gap. |
23rd Jun 2017, 8:53 am | #10 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Replacing the upper cylinder which contains the heads is not difficult at all.
The spacer shim(s) can be easily made using an old 35mm film negative now called shim. The most important point is to make sure the heads are kept out of the way of the shim. Because it is easy to damage the heads, make sure that they dont hit the cassette carriage when aligning the drum to the shaft. Place the shim where the upper cylinder meets the fixed drum and rotate the heads out of the way. Lower the cylinder onto the shim, tighten the fixing nut whilst, using a pair of long nose pliers, stopping the threaded screw from turning. When tightened, lift the cylinder slightly and remove the shim. Job done. |
24th Jun 2017, 12:26 pm | #11 |
Pentode
Join Date: Oct 2016
Location: Ware, Herts, UK
Posts: 169
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Thanks for the advice simpsons.
Tried this today and didn't quite get the result I was hoping for. Using the film negatives as spacers/shims, I now get a constantly rolling picture, as if the machine cannot track. I also experimented with different, larger gaps between upper and lower head drum and as the gap increased the picture stabilised (stopped rolling) but an increasing bottom part of the screen was "grey noise" as if only part of the video track was being scanned. This made sense to me as the heads were effectively scanning higher and higher on the tape as I made the head gap bigger, missing more and more of the bottom of the tape. But... why when I make the gap the correct height (using the film negatives as spacers) would I lose all tracking and have the picture continuously roll? Any ideas? Rob |
24th Jun 2017, 6:04 pm | #12 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Shouldn't the track following servo (the bit that drives those piezo actuators that carry the heads) adjust the heads to follow the track and thus the height of the upper drum is not too critical (provided it's not so far out that the servo can't cope)?
Is it possible there's a problem with this servo or the power supply (it uses a couple of high-ish voltage rails)? |
25th Jun 2017, 10:53 pm | #13 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Hi Rob
I suggest that you first reset the head height using just one thickness of the 35mm negative which is the same thickness as the original philips shims. It is possible that the head is past its sell by date but first listen to make sure the sound is at the right speed and also see that the head is spinning without hunting. The heads rotate at some 1500 rpm so that with tape passing at a constant speed, each rotation scans or plays back a frame of the 50 Hz video. The video servo will compensate for some errors as described in the service manual, but only within certain limits. If possible try another recording or make one to see what happens. There are certain pre-set adjustments to the servo but unless they have been got at, I would leave them alone. Changing a head shouldn't require further work. Chris . |
26th Jun 2017, 3:45 pm | #14 |
Pentode
Join Date: Oct 2016
Location: Ware, Herts, UK
Posts: 169
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Re: Philips V2000 - 2nd Generation Video Head compatibility
Thanks Chris/Tony.
I am quite puzzled by this -and appears half of the service manual I have is missing which isn't helping -esp the DTF stuff. Agree it could be the heads on their way out, but looking at them carefully, they don't appear chipped or broken. Audio is always perfect BTW and I can't hear any obvious movement/hunting on the heads during play. Setting the head gap back to the width of one-35mm negative , I get a rolling picture on all tapes, as if the DTF tracking isn't working at all (the tapes play fine on my VR2022). To Tony's point - if the head gap is made larger, surely the DTF should activate to try and follow the tape - not just show a grey-noise bar happily at the bottom of the screen! It is possible the machine was "played with" before I got it. Have either of you got a copy of a complete VR2324 manual that includes the DTF circuitry and adjusters? I have no idea how to test the actuator servos (or where they are - although I assume inside the drum?) - but am suspecting they are the issue. R. |
27th Jun 2017, 12:13 am | #15 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
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Re: Philips V2000 - 2nd Generation Video Head compatibility
OK
Google the Philips VR2220, visit page 2 and www.doctsf.Modèle : VR 2220. Année : 1983 schematic and circuit description can be downloaded albeit in Dutch. This should give you enough to see how Philips designed the VR2324 you have. I will pm you a copy of the Television Magazine description of the V2000 DTF. As the tape works in your other machine see if you can record something on the VR2324 and see what the VR2020 does with it. Chris |