Schematic required NTP Phasing scope
Chris Notton
Anyone got the schematic for a NTP 277-500 phasing scope (Goniometer) as
fitted to SSL desks etc? The people who now own NTP are very helpful but
say they didn't receive documentation for this product when they took
over the company!!
Anyone gotta circuit? Would save me a shedload of time.
Also looking for a new tube (AEG Telefunken D7-16 GJ) when I get it
fixed. It is for a restoration job I'm working on at the moment.
Pip pip
--
Chris Notton
Replace "nospam" with my surname to reply by email
Sostituisca il "nospam" con il mio cognome per rispondere
}<////(*>
Scott Dorsey
>Hi Guys,
>
>Anyone got the schematic for a NTP 277-500 phasing scope (Goniometer) as
>fitted to SSL desks etc? The people who now own NTP are very helpful but
>say they didn't receive documentation for this product when they took
>over the company!!
>
>Anyone gotta circuit? Would save me a shedload of time.
I don't, but I can guess it. What is the thing doing?
>Also looking for a new tube (AEG Telefunken D7-16 GJ) when I get it
>fixed. It is for a restoration job I'm working on at the moment.
Try Sphere Research in Canada, www.sphere.bc.ca. They have a good stock
on old scope tubes. You can probably also get Hawkeye Picture Tubes to
rebuild the old tube for you, and it might be cheaper.
The GJ means it has a short persistance phosphor. You may want to consider
replacing it with the GM long persistence phosphor. The tube may be easier
to find, and personally I tend to like the long persistence on a phase meter.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Chris Notton
Well the PSU dies after a variable amount of time, there is a voltage
multiplication circuit that I think is collapsing. I thought that
getting a circuit diagram for such a common accessory would be easy but
no go.
I will check out the new tube suppliers after I get it fixed as it has
quite a burn on it.
Scott Dorsey
>
>Well the PSU dies after a variable amount of time, there is a voltage
>multiplication circuit that I think is collapsing. I thought that
>getting a circuit diagram for such a common accessory would be easy but
>no go.
Is the multiplier open to air, or is it all sealed up in epoxy? Does it
smell funny?
You got the choice of a diode going open when it gets hot or a ceramic
cap that is cracked and goes open when it gets hot. If you have a
meter with an HV probe, it can help a lot. But my tendency would be to
just shotgun all the caps and diodes in the multiplier out. You can get
a roll of 1N4007s for a couple pennies each.
Do get the HV probe and make sure there's still something coming off the
transformer.... the multiplier parts in general are much more likely to
fail open than shorted so if you actually measure low voltage coming
off the transformer, it's probably time to look earlier in the circuit.
Chris Notton
I eventually obtained a manual, set-up info & diagrams of the NTP
phasing scope & have successfully repaired it! The owner has given me
permission to offer the information to any other owners who need it, so
if you have got one.......
The problem was the CMOS "chopper" circuit that was used to generate the
h.t. voltages. Oh yes, & the intensity control was not doing anything!
Tricky little buggers these, took flippin ages!
Still can't find a new tube though so if anyone comes across a AEG
Telefunken D7-16 GJ or GM (thanks Scott) please drop me an email
bre...@ase.co.za
> In article says...
> > Chris Notton
We are servicing an SSL console and the NTP 277-500 was serviced by a previous technician. This scope was not working thereafter. We need the schematics to be able to repair the unit. Would you be able to send me the above mentioned?
Brett
mako...@yahoo.com
> >
> > Still can't find a new tube though so if anyone comes across a AEG
> > Telefunken D7-16 GJ or GM (thanks Scott) please drop me an email
> >
>
Mark
Scott Dorsey
can reach him at chris at mtr90.com, I believe.
bre...@ase.co.za
Regards
Brett
mlasy...@gmail.com
John Williamson
> I purchased NTP 277-500 on ebay, now I managed to connect it but intensity is very bad. If turn intensity knob fully clockwise I can see some light green signal, but it can be seen only in dark. Do anyone have any idea what is wrong? Thanks.
>
electronics for a few decades.
If it's a CRT tube, the three main possibilities are not enough HT, too
much voltage on the control grid and not enough emission from the heater.
The grid voltage should go to almost zero at the bright end of the
control run, and may be a hundred volts or so negative at the dim end of
the control run, while heater voltage should be 6.3 volts ac for most
tubes. If you can safely do it, check the HT voltage on the accelerating
electrode, which should be high, and may be up to 2kV. The connection is
normally under an insulating cap at the display end of the tube and
fairly hard to get at.
If the focus control works (It may be on the PCB, not the front panel),
and you can get a sharp spot with the timebase turned off or both inputs
with no signal, the HT is probably okay, and if you defocus the spot,
you can get an image of the cathode on the face of the tube, which
should show even emission all over. Unevenness may mean the tube is shot.
If it's an LCD display, then the backlight will be the problem, with
either the lamp or inverter having failed, or there may be a bad
connection between the brightness control and the inverter. If you get
anything at all on the display, then the display and its driver are
probably okay.
--
Tciao for Now!
John.
avcorpmic...@gmail.com
I have access to the original Telefunken tubes.
Scott Dorsey
>Has anybody got the schematic for the NTP 277-500 ?
>I have access to the original Telefunken tubes.
any longer, but he's the guy with the original problem and he did eventually
come up with the schematic of the thing.
Chris Notton
> In article <5e98e80f-6b50-4599...@googlegroups.com>,
> <avcorpmic...@gmail.com> wrote:
> >Has anybody got the schematic for the NTP 277-500 ?
> >I have access to the original Telefunken tubes.
>
> This thread is nearly a decade old now. Chris Notton doesn't hang out here
> any longer, but he's the guy with the original problem and he did eventually
> come up with the schematic of the thing.
> --scott
>
contact me on www.otari.co.uk
Regards to all.
Thomas de Fraguier
Long shot but I am looking for the schematics / diagram / manual for this unit. What's its power consumption ?
The otari.co.uk website is down so here is my only shot at contacting you for such info.
Thanks a lot in advance
Thomas
John Williamson
> Hello
> Long shot but I am looking for the schematics / diagram / manual for this unit. What's its power consumption ?
> The otari.co.uk website is down so here is my only shot at contacting you for such info.
>
> Thanks a lot in advance
>
> Thomas
>
does not use a secure connection protocol. (It is linked to via http,
not https. This problem is becoming more and more common recently.))
John Williamson
> Long shot but I am looking for the schematics / diagram / manual for this unit. What's its power consumption ?
> The otari.co.uk website is down so here is my only shot at contacting you for such info.
>
> Thanks a lot in advance
>
> Thomas
>
linked to from this page.
https://web.archive.org/web/20211201002145/http://www.otari.co.uk/
Scott Dorsey
>Le mardi 8 ao=C3=BBt 2017 =C3=A0 18:42:57 UTC+2, fonta...@googlemail.com a =
>=C3=A9crit=C2=A0:
>> On Monday, 5 December 2016 14:22:31 UTC, Scott Dorsey wrote:=20
>> > In article <5e98e80f-6b50-4599...@googlegroups.com>,=20
>> > <avcorpmic...@gmail.com> wrote:=20
>> > >Has anybody got the schematic for the NTP 277-500 ?=20
>> > >I have access to the original Telefunken tubes.=20
>> >=20
>> > This thread is nearly a decade old now. Chris Notton doesn't hang out h=
>ere=20
>> > any longer, but he's the guy with the original problem and he did event=
>ually=20
>> > come up with the schematic of the thing.=20
>> > --scott=20
>> > "C'est un Nagra. C'est suisse, et tres, tres precis."
> if anybody needs them.=20
>> contact me on www.otari.co.uk=20
>> Regards to all.
>
>
>Hello
>Long shot but I am looking for the schematics / diagram / manual for this u=
>nit. What's its power consumption ?=20
>The otari.co.uk website is down so here is my only shot at contacting you f=
>or such info.
Chris Notton used to be at "chris at otari dot co dot uk" for email. His
phone number was +44 (0)1525 403491.
--scott
--