Dec 2 TV 0

"Future proof" Philips 32 inch IDTV built in ON DIGITAL slot CRT, since the
2 Dec rescan "no channels found"
Sagem ITD 64, continual restarts.
Astratec DV3, No BBC.
Oh for the days of just buy a tv plug in and watch.

Yes, I'm oldd enough to remember the early days of mooted 625 line where one
set came out proclaiming it was 625 ready, as indeed it could switch to that
linerate, but it had no circuit to decode the new negative going video or
the fm sound, though one could plug in a UHF tuner which was of course never
made.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"/\BratMan/\" wrote in message
...
"Future proof" Philips 32 inch IDTV built in ON DIGITAL slot CRT, since
the 2 Dec rescan "no channels found"
Sagem ITD 64, continual restarts.
Astratec DV3, No BBC.
Oh for the days of just buy a tv plug in and watch.

Yes, I'm oldd enough to remember the early days of mooted 625 line where one set came out proclaiming it was 625 ready, as indeed
it could switch to that linerate, but it had no circuit to decode the new negative going video or the fm sound, though one could
plug in a UHF tuner which was of course never made.

Brian

I think you are referring to the Thorn 900 chassis.

--
Graham.

%Profound_observation%

This was an appalling scam in the 60's - the TV's boasted dual standard, but
most of the circuitry for 625 lines was not there!

The other problem was that at 625 lines the PL 85/805 line output valve used
to blow fairly quickly...

"Brian Gaff" wrote in message
m...
Yes, I'm oldd enough to remember the early days of mooted 625 line where
one set came out proclaiming it was 625 ready, as indeed it could switch
to that linerate, but it had no circuit to decode the new negative going
video or the fm sound, though one could plug in a UHF tuner which was of
course never made.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"/\BratMan/\" wrote in message
...
"Future proof" Philips 32 inch IDTV built in ON DIGITAL slot CRT, since
the 2 Dec rescan "no channels found"

Sounds like early Philips digital tuners. They stopped working on
switchover (Philips eventually admitted this would happen about a year ago.

Sagem ITD 64, continual restarts.
Astratec DV3, No BBC.

Cold boot them and try again.

Oh for the days of just buy a tv plug in and watch.

In article ,
says...

This was an appalling scam in the 60's - the TV's boasted dual standard, but
most of the circuitry for 625 lines was not there!

Typical time-line for one manufacturer (Bush)

TV105 series: (1961) Largish rectangular buttons marked 405 & 625 under
the 4 VHF tuner buttons. 405/625 buttons connected by rods to a paxolin
plate (only) fixed via a central pivot, so that one came out when the
other was pressed. The chassis was 405 only

TV115 series: (1962) TV105 dummy buttons replaced by a large horizontal
lever which operated the timebase system switch. 405/625 timebase, RF/IF
section entirely 405.

TV115L series: Late variant of the TV115 with dual standard IF strip, so
chassis now fully dual standard except for the UHF tuner.

TV125 series: (1963) Internally identical to the TV115L with external
design change - VHF tuner rotated through 90 degrees with buttons now
vertical (tuner position remained at bottom of the cabinet). Four dummy
UHF buttons at the top with matching 405/625 buttons arranged
horizontally in the centre.

TV125U series: First full 405/625 set released.

Conversion kits were 8 guineas for the '115L & '125 (UHF tuner only but
the '125 kit included a little 'U' label to stick on the back to modify
the model number!)

Fifteen guineas got you the '115 kit which also meant replacing the IF
strip.

As all these sets were marketed as being 'fully convertible', there was
a kit for the '105 series produced, though, at around £30, I doubt many
were sold! All these prices, of course, excluded labour costs!

Note that, in those days, new models were announced at the annual Radio
Show (later replaced by individual trade shows) held during the summer,
so the dates quoted above relate to an autumn release.

Thus the TV125 series was released about 6 months before BBC2 started
and was produced in two versions, with and without the UHF tuner,
although I can't remember if there was a delay releasing the TV125U. The
price differential - surprise, surprise - was eight guineas!

Of course, as BBC2 was only initially available from Crystal Palace (and
relays) all of the unconverted sets elsewhere in the country got
progressively older while they were waiting, which must have made
conversion costs increasingly unattractive ...

The other problem was that at 625 lines the PL 85/805 line output valve used
to blow fairly quickly...


I'm confused here or, at least, I think you are!

The PL81 line output valve had largely been superceded by the PL36
which, I think all these sets used. I don't recall them having a shorter
life working at 625 lines, though.

I'm sure you're thinking of the PCL85/805 FIELD output valve.

The PCL85 was a very badly designed valve which failed repeatedly. The
replacement PCL805 was better - these tended to have a shortened life,
though, if the cathode bias resistor which had been badly cooked by its
predecessor hadn't been checked and replaced if necessary. (These carbon
composition resistors tended to drop in value quite considerably and
seriously over-ran the replacement valve if not replaced.)

As there was no difference in working conditions for these valves on
either system, there was no difference in lifetime.

--

Terry

I'm sure you're thinking of the PCL85/805 FIELD output valve.

The PCL85 was a very badly designed valve which failed repeatedly. The
replacement PCL805 was better - these tended to have a shortened life,
though, if the cathode bias resistor which had been badly cooked by its
predecessor hadn't been checked and replaced if necessary. (These carbon
composition resistors tended to drop in value quite considerably and
seriously over-ran the replacement valve if not replaced.)

As there was no difference in working conditions for these valves on
either system, there was no difference in lifetime.


In the Phillips series they had a drop off resistor which as it 's name
implied they dropped of their mounting when the current through them got
too much, or a heather cathode short caused the same sorta thing then
the 250 uF capacitor took the current with a good bang and shower of
conductive electrolyte all over the board ..

Still you could change well for those repairs especially ones that went
BANG!.....
--
Tony Sayer

On Sun, 6 Dec 2009 17:11:11 +0000, tony sayer wrote:

heather cathode

I like it!

Go Green. Use organic components.

--
Peter Duncanson
(in uk.tech.digital-tv)

In article , says...


In the Phillips series they had a drop off resistor which as it 's name
implied they dropped of their mounting when the current through them got
too much, or a heather cathode short caused the same sorta thing then
the 250 uF capacitor took the current with a good bang and shower of
conductive electrolyte all over the board ..

Yes, I remember the Philips chassis in question.

The 'drop-off' resistors (there were several) were soldered to the
underside of flat metal stand-off tags.

You always knew when one dropped off - as you removed the back of the
TV, you heard it rolling around in the bottom ...

.... the PCL805 cathode bias resistor always seemed to me underrated, by
comparison with earlier sets. This was probably a clever bit of design,
though we didn't look at that way at the time, as it drew attention to a
problem that many had overlooked in the past ...

.... they relied, for continued safety, on replacement using the same
component fitted in the same way. If the local cowboy wrapped the wires
around the tags, all bets were off!


Still you could change well for those repairs especially ones that went
BANG!.....

Unlike you, I didn't work for a rip-off outfit. We prided ourselves on
doing a good job at a reasonable price - but I knew an awful lot who
didn't!

--

Terry

In article , Terry Casey
scribeth thus
In article , says...


In the Phillips series they had a drop off resistor which as it 's name
implied they dropped of their mounting when the current through them got
too much, or a heather cathode short caused the same sorta thing then
the 250 uF capacitor took the current with a good bang and shower of
conductive electrolyte all over the board ..

Yes, I remember the Philips chassis in question.

The 'drop-off' resistors (there were several) were soldered to the
underside of flat metal stand-off tags.

You always knew when one dropped off - as you removed the back of the
TV, you heard it rolling around in the bottom ...

... the PCL805 cathode bias resistor always seemed to me underrated, by
comparison with earlier sets. This was probably a clever bit of design,
though we didn't look at that way at the time, as it drew attention to a
problem that many had overlooked in the past ...

... they relied, for continued safety, on replacement using the same
component fitted in the same way. If the local cowboy wrapped the wires
around the tags, all bets were off!


Still you could change well for those repairs especially ones that went
BANG!.....

Unlike you, I didn't work for a rip-off outfit. We prided ourselves on
doing a good job at a reasonable price - but I knew an awful lot who
didn't!


It wasn't me setting the charges it was the blokes who owned the firm
and many times they told us if we priced everything as we perhaps ought
we wouldn't be able to have a service dept in the first place.

In fact it was subsidised by sales.

Around here there used to be a few service only outfits, aren't any
around anymore in fact one long standing one went tits up the other
week. Now only the one left and the national multiples are totally
gormless when it comes to giving any sensible info at all to
customers!.....


--
Tony Sayer