New Philips N1700 (VCR-LP) heads for a 1978 video recorder?

[@vwestlife]

Seeing that clip from the service manual reminded me that the factory shop manuals for Volkswagen cars also refer to electrical ground as "mass". It's a literal translation of the German word "masse".

[@Ragnar8504]

Yes, that's the German term used for DC systems, especially in electronics and vehicles. I think it refers to a common conductor or potential that's not referenced to any outside potential as the English terms ground or earth would suggest. Switch SK15 is linked to the Eject button and earths point R2 when the button is pressed. That connects the base of TS105 to earth via resistor R140 and TS105 no longer conducts.

[@telocho]

Dutch use massa as well for ground.

[@JacGoudsmit]

I suspect that someone may have gotten those new heads, put them in their recorder and put the old heads from their recorder back in the box.

[@electrajojo]

Those NOS Heads are most likely fine as the Philips N1700 heads required a "break in" period at the factory in which a special tape with abrasion was used to speed up the process during calibration.

[@crashbandicoot4everr]

I think that process is called lapping. I saw it mentioned on a Sanyo Beta service manual.

[@lorevids_]

Good to see the N1700 saga continue! There are a couple of things to try, you could use an oscilloscope to look at the FM envelope to get more clues. It is on the PCB underneath on the right, F21. Other thing to try is to record something with the presumably new head, and see if it plays back well on this machine (my guess is it does), and with the known good head (probably not).

[@video99couk]

I did look at the RF envelope of an N1700 some weeks ago, that's when I found out that there is no head switching signal!

[@more.power.]

Thank you Colin makes the repair difficult when the parts are faulty.

[@MVVblog]

WOW NOS head drum!!!

[@frankowalker4662]

I'm wondering what the recording quality is like with those heads ? Maybe that would give some more information.

[@TTVEaGMXde]

In Hamburg, a dealer had also received several non-functioning VCR head drums from PHILIPS.

[@dannyjaar]

new head must playing in

[@bjarneanthony1363]

Colin can you make video of the Philips n 2400 casettedeck its the first stereo casettedeck in 1971.very famous to day on the internet. Regard Anthony

[@snap_oversteer]

I'd try recording on that drum and see if it can play its own recordings and subsequently try to play it back on other decks. Or maybe just try it playing for couple of hours to see if it wears in? I'm of course just guessing, I have never seen any Philips VCR in person let alone work on it.

[@fsfs555]

It looks like the green head's cracked. There's a fine black line that appears to go across the lower coil protrusion. It could be a scratch but then the surface on either side doesn't quite line up.

[@video99couk]

I thought that, but then the other heads looked similar.

[@tremorist]

Professional machines also came with onboard diagnostics and they were made in order to be repaired on location. No headaches with the right service contract. Machines for domestic use on the other hand... 🤣

[@BongbongA99]

Hello Colin, It's funny that you have one with a gouge in it - I have one like there here. I wonder what that was done for? Interesting!

[@cbehr91]

I thought BASF was one of the superior brands of VHS blanks as well, although as time has gone on I've encountered BASF tapes that shed oxide at more a severe rate than other brands.

[@mrnmrn1]

80s BASF VHS tapes were good, up until about '93. From the mid '90s till end of production in the mid '00s they made some horrible VHS tapes. I have many, including prerecorded, which are simply unplayable, because the tape on the supply spool stuck together so much that it causes excessive back tension. Sometimes it even stalls the drum. The only fix is to FF then REW the cassette in a VCR that does not lace up the tape during winding. After that it usually becomes playable, but only for a short time, if you let it sit for a few months or sometimes even just weeks, it will become unplayable again.

[@Capturing-Memories]

Is the adjustment of the head chips called the dihedral adjustment? I've heard that term before.

[@azshaw123]

That is beta only i think.

[@livinlifetothefullest2750]

​@azshaw123 it's mentioned both makes of heads that were manufactured by for the Beta's eg sl-6c early fat, sl-hf 100 smaller mid 80s onwards etc etc

[@bob-s-bit-s]

hi the trolls will be all over you the decks are a right pain to work on as you are finding why i stopped fixing them there's alot of fans love to have them in there cave i go after things i can get working for my cave i fine it vert sad when things just don't go right i used to have a audio vog youtube channel along time ago with pic's there's alot out there try the dump gear on you all the time bob

[@MrHandymon]

There used to be a service jig which was made from square steel tubing that had cranked legs at the back. The machine was sat on the frame and was lifted off the bench about nine inches by the height of it's legs, the frame could be tilted back, while the machine was on it, so it sat at about seventy five degrees to vertical, you could then work on the underside of the mechanism when the access door was removed, while it was running.

[@mdftrasher]

I think faulty (new) head

[@guimbadriver]

this format never arrived here in brazil only u matic v cord beta video 2000 and vhs

[@video99couk]

It was never released (beyond a few trial machines) in the NTSC television standard.

[@guimbadriver]

@@video99couk Less in M-PAL color tv standard here in brazil...

[@magnusterminus4728]

Still have 9 new N1500 drums heads in original Philips packaging 😊

[@video99couk]

Wow! I could certain make use of one or two of those! Any for sale?

[@davy642]

I'm also interested if you sell them

[@magnusterminus4728]

@@davy642 I am willing to sell but pickup only in the Netherlands.

[@davy642]

@@magnusterminus4728 Oh damn :( even if I pay you the shipping costs? I am in Switzerland and I have 4 devices with defective heads

[@magnusterminus4728]

@@davy642 Hi, if you come over I will put the drum in your N15XX machine so you can see it is running fine. I will be taking the drum from an unopened original Philips box, you can choose which one of the 8 left you want. I will test your machine with a used drum first to see it is operating 100% before I put the new drum in. I am willing to sell 2 to 3 drums, the remaining I will use to refurbish a couple of N1512's.

[@maurice2vd6]

May be the label is wrong? And its actual a N1500/N1502 head? could be a mis labeling, Who knows. 1500/1700 the angle of the heads are slightly different. Thought it was the angle of the tiny split that differ from 1500-1700 Then also mark little magnet , it is to syncpuls head motor. Then check PCB coil (Rotating transformer) that transfer head signal to the drum. See servo Head , point 17 of U236 with repetition of 25Hz to see if head K6 is pick up that little magnet. May be wrong position of that magnet? Would be interesting to figure out the problem of that head, Indeed a Videohead tester. But beware they differ from use of Beta VCR VHS heads. Sometimes type of tester needs to be calibrated first. Mostly measure uH, So a very good coil tester probably would do also. As you have working heads you can compare results. If all seems to be OK, or similar, may be you have to re-adjust tone-axel as that needs to be square, see service manual (N1700), also from stamp 816 onwards east/west adjust also. Misalignment would cause Sync problems due to head/tape contact and so less sync amplitude. Then square angle of pitch roller and then after that also a dynamic adjustment of that roller. All indicating when problems with sync. This according Philips servive note. N1700 VCR14 1979.

[@video99couk]

You would get virtually no picture and absolutely no colour from an N1500 head.

[@pe1dnn]

N1500 heads are straight. That's why N1500 has a guard gap between the tracks to prevent cross talk. On N1700 they are slanted, both in a different direction so alternating tracks have a very different azimuth (VHS, Beta, U-matic etc all use the same trick). This enabled having the tracks next to each other with no gap, instantly doubled the recording time. If you look at the N1502 and then N1700 then you will see the electronics are very, very similar, only the N1502 only has a much bigger capstan to move the tape faster and a different head drum. So converting an N1502 to an N1700 must have been very easy for Philips. Just reduce the capstans and change the head drum to one with slanted heads. Except for just regular improvements that's the only key difference between the two. By the way, there needs to be a metal bracket with a small piece of graphite that touches to the top of the head to provide a path to ground to avoid a static charge buildup on the drum. However this may start to squeal when it wears, so maybe that's why it was taken out? One trick was to flip the small graphite piece when the tip of the drum made an impression on one side. Here it seems to be gone completely. But this is what the pointy tip is on the drum. No idea what the effects are if it is missing, it could present a problem when using it.