[Engineer[_2_]]

Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built "like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I bought the
Ferrograph a few years ago, along with a few blank and used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback equalizer
(fixed, too short - added a shielded extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose glass (fixed
the MC movement with contact cleaner and used epoxy to fix the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the EZ80 (6V4)
rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! Still worrying...
I sold the whole lot (on Craigslist, actually, not eBay) to a vintage
tape recorder and music enthusiast in Toronto who plans to use it for
original contemporary music mixing (analog) - a good use for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian Air & Space
Museum for our Lancaster project.
Cheers,
Roger

[Ian Bell[_2_]]

Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built "like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I bought the
Ferrograph a few years ago, along with a few blank and used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback equalizer
(fixed, too short - added a shielded extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose glass (fixed
the MC movement with contact cleaner and used epoxy to fix the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the EZ80 (6V4)
rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! Still worrying...
I sold the whole lot (on Craigslist, actually, not eBay) to a vintage
tape recorder and music enthusiast in Toronto who plans to use it for
original contemporary music mixing (analog) - a good use for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian Air & Space
Museum for our Lancaster project.
Cheers,
Roger

Ferrographs are of course well known and loved over here in the UK. In
the 50s and 60s Ferrograph and Brenell were THE semi pro makes that
hi-fi folk in the UK aspired to. I have an old Series 4 myself - the
miltary version that was apparently used record sonar on submarines. The
consumer types were built like and brick s**thouse as you say but the
miltary versions were built like battleships and encased in a tough
metal case.

As you discovered they are fairly easy to service and repair - just be
careful with the grade of oil you use for lubrication.

Cheers

ian

[John Byrns]

In article
,
Engineer wrote:

Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built "like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I bought the
Ferrograph a few years ago, along with a few blank and used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback equalizer
(fixed, too short - added a shielded extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose glass (fixed
the MC movement with contact cleaner and used epoxy to fix the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the EZ80 (6V4)
rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! Still worrying...
I sold the whole lot (on Craigslist, actually, not eBay) to a vintage
tape recorder and music enthusiast in Toronto who plans to use it for
original contemporary music mixing (analog) - a good use for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian Air & Space
Museum for our Lancaster project.
Cheers,
Roger

Hi Roger,

You mention that the EZ80 (6V4) rectifier can develop heater to cathode
short and take out the mains transformer, is the EZ80 more prone to this
problem than other heater cathode rectifier tubes? I have several
pieces of equipment that use the EZ80 and never realized that it was a
problem tube, now you have me worried! It does seem to be a hard to
find tube. I did have multiple failures of this tube in one piece of
equipment I owned back in the 1960s, but I don't know if heater to
cathode shorts were the problem, if they were the line fuse saved the
power transformer several times, the fuse was marginally rated and would
tend to blow randomly for no apparent reason, perhaps it was a good
thing that I resisted the temptation to replace it with a larger fuse
than was specified.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

[Engineer[_2_]]

On Aug 17, 7:09*pm, John Byrns wrote:
In article
,





*Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built "like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I bought the
Ferrograph a few years ago, along with a few blank and used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback equalizer
(fixed, too short - added a shielded *extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose glass (fixed
the MC movement with contact cleaner and used epoxy to fix the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the EZ80 (6V4)
rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! *Still worrying...
I sold the whole lot (on Craigslist, actually, not eBay) to a vintage
tape recorder and music enthusiast in Toronto who plans to use it for
original contemporary music mixing (analog) - *a good use for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian Air & Space
Museum for our Lancaster project.
Cheers,
Roger

Hi Roger,

You mention that the EZ80 (6V4) rectifier can develop heater to cathode
short and take out the mains transformer, is the EZ80 more prone to this
problem than other heater cathode rectifier tubes? *I have several
pieces of equipment that use the EZ80 and never realized that it was a
problem tube, now you have me worried! *It does seem to be a hard to
find tube. *I did have multiple failures of this tube in one piece of
equipment I owned back in the 1960s, but I don't know if heater to
cathode shorts were the problem, if they were the line fuse saved the
power transformer several times, the fuse was marginally rated and would
tend to blow randomly for no apparent reason, perhaps it was a good
thing that I resisted the temptation to replace it with a larger fuse
than was specified.

--
Regards,

John Byrns

Surf my web pages at, *http://fmamradios.com/- Hide quoted text -

- Show quoted text -

John, the Ferrograph actually had a 6V4 in it which is the American
equivalent of the European EZ80 (glass, 9 pin.) They share the 6.3
vac heater, so any H-K short is across the B+, hence the MT is
threatened. I had a 6V4 fail in a Phillips radio a while back but
caught it in time by shear luck as I had a meter on the B+ as a final
check when "zipping up". There are several similar tubes in octal,
the 6X5 comes to mind. I don't know if any are worse than the others
but I've heard complaints about the 6X5... of course, the plural of
anecdote is not data! Anyway, my position is, why risk it. MT's are
expensive so, in radios, I replace these tubes with 1N4007's. I have
also put a fast blow fuse in the MT CT to ground. Perhaps I am a bit
paranoid but I much prefer the rectifiers with a separate 5 vac
heater. Sorry to be inexact. What do others think?
Cheers,
Roger

[Ian Iveson]

Engineer

Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on,
but I did have
a British Ferrograph tape recorder on the bench recently,
a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built
"like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I
bought the
Ferrograph a few years ago, along with a few blank and
used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback
equalizer
(fixed, too short - added a shielded extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose
glass (fixed
the MC movement with contact cleaner and used epoxy to fix
the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the
EZ80 (6V4)
rectifier. These can develop heater to cathode short and
take out the
mains transformer. I toyed with replacing it with two
1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it
original. I
really hope this was not a bad decision! Still
worrying...
I sold the whole lot (on Craigslist, actually, not eBay)
to a vintage
tape recorder and music enthusiast in Toronto who plans to
use it for
original contemporary music mixing (analog) - a good use
for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian
Air & Space
Museum for our Lancaster project.

Can a fuse be used to protect the transformer?

Ian

[Doug Bannard]

"Engineer" wrote in message
...
On Aug 17, 7:09 pm, John Byrns wrote:
In article
,





Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built "like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I bought the
Ferrograph a few years ago, along with a few blank and used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback equalizer
(fixed, too short - added a shielded extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose glass (fixed
the MC movement with contact cleaner and used epoxy to fix the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the EZ80 (6V4)
rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! Still worrying...
I sold the whole lot (on Craigslist, actually, not eBay) to a vintage
tape recorder and music enthusiast in Toronto who plans to use it for
original contemporary music mixing (analog) - a good use for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian Air & Space
Museum for our Lancaster project.
Cheers,
Roger

Hi Roger,

You mention that the EZ80 (6V4) rectifier can develop heater to cathode
short and take out the mains transformer, is the EZ80 more prone to this
problem than other heater cathode rectifier tubes? I have several
pieces of equipment that use the EZ80 and never realized that it was a
problem tube, now you have me worried! It does seem to be a hard to
find tube. I did have multiple failures of this tube in one piece of
equipment I owned back in the 1960s, but I don't know if heater to
cathode shorts were the problem, if they were the line fuse saved the
power transformer several times, the fuse was marginally rated and would
tend to blow randomly for no apparent reason, perhaps it was a good
thing that I resisted the temptation to replace it with a larger fuse
than was specified.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/- Hide quoted text -

- Show quoted text -

John, the Ferrograph actually had a 6V4 in it which is the American
equivalent of the European EZ80 (glass, 9 pin.) They share the 6.3
vac heater, so any H-K short is across the B+, hence the MT is
threatened. I had a 6V4 fail in a Phillips radio a while back but
caught it in time by shear luck as I had a meter on the B+ as a final
check when "zipping up". There are several similar tubes in octal,
the 6X5 comes to mind. I don't know if any are worse than the others
but I've heard complaints about the 6X5... of course, the plural of
anecdote is not data! Anyway, my position is, why risk it. MT's are
expensive so, in radios, I replace these tubes with 1N4007's. I have
also put a fast blow fuse in the MT CT to ground. Perhaps I am a bit
paranoid but I much prefer the rectifiers with a separate 5 vac
heater. Sorry to be inexact. What do others think?
Cheers,
Roger
----------------------------------------------------------------------------------------------------------------


Roger:

The 6X5 is well known in the vintage radio community for being problematic.
Most of the failures that occur in 6X5s are not heater to cathode, but are
plate to plate or plate to cathode, due to the peculiar construction of the
6X5.

The 6X4, 6V4(EZ80), 6CA4(EZ81) as well as the 6AX5 do not share the same
type of internal construction as the 6X5. I don't think I have ever seen an
H-K short in these types in the 45 years I've been working on equipment
using them.

What I have seen is a few catastrophic failures where arc-over occurs
between plate and cathode, often ending in a piece of cathode material
jammed between plate and cathode resulting in a short. Invariably this arc
over was caused by too large an input filter cap, too small a transformer
source resistance, or both. As long as these tubes (other than the 6X5) are
applied as per their designer's recommendations, you should have no
problems.

It you're worried, fuse(fast blow) the two plate leads. I do this with sets
using 6X5s, and it protects the power transformer nicely.

The use of 1N4007s however is another story. They're rated for 1kV reverse
voltage. If you use these on a 300-0-300 power transformer, you don't have
enough safety margin (1 kV diode run at 848 volts!!), and have virtually
none at high AC line voltage. I've seen lots of power transformers taken
out by the misapplication of these buggers, and routinely use two or more
4007s in series to give me a reasonable safety margin. Stick 1000pF @1kV
across each to help equalize the reverse voltage as well to provide a crude
measure of switching noise suppression.

Best Regards : Doug Bannard, P.Eng.

[Engineer[_2_]]

On Aug 18, 6:27*am, "Ian Iveson"
wrote:
Engineer





Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on,
but I did have
a British Ferrograph tape recorder on the bench recently,
a series 4,
open-reel, 1950's vintage.
This was a resonably high-end machine at that time.. built
"like a
brick outhouse", as they say, and very heavy! (50 lbs)
I had an original manual, found on eBay shortly after I
bought the
Ferrograph a few years ago, along with a few blank and
used tapes.
It had a few problems... easily fixed, viz:
-- stuck 7 1/2 ips idler wheel (freed-up and lubed),
-- motors and capstan needed lubrication (done),
-- dirty heads (cleaned),
-- intermittent cable from deck speed switch to playback
equalizer
(fixed, too short - added a shielded *extension),
-- stuck record meter (a 1 mA FSD MC meter) with loose
glass (fixed
the MC movement with contact cleaner and used epoxy to fix
the glass -
not quite so easy as the rest!)
-- open set-zero pot for the meter (replaced)
-- general dirt from over 50 years...
All tubes were good. One vulnerable item in this TR is the
EZ80 (6V4)
rectifier. These can develop heater to cathode short and
take out the
mains transformer. I toyed with replacing it with two
1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it
original. I
really hope this was not a bad decision! *Still
worrying...
I sold the whole lot (on Craigslist, actually, not eBay)
to a vintage
tape recorder and music enthusiast in Toronto who plans to
use it for
original contemporary music mixing (analog) - *a good use
for an old
warrior!
Now it's back to a Bendix "boatanchor" for the Canadian
Air & Space
Museum for our Lancaster project.

Can a fuse be used to protect the transformer?

Ian- Hide quoted text -

- Show quoted text -

Yes, I have used a 0.5 amp fast blow fuse in the mains transformer CT
to ground... but never had a failed 6V4 (EZ80) shorting H-K to prove
it!
Cheers,
Roger

[Engineer[_2_]]

On Aug 18, 9:52*am, "Doug Bannard" wrote:
"Engineer" wrote in message

...
On Aug 17, 7:09 pm, John Byrns wrote:

(snip)


... rectifier. These can develop heater to cathode short and take out the
mains transformer. I toyed with replacing it with two 1N4007's, plus
an 82 ohm WW (as I do in radios), but in the end I left it original. I
really hope this was not a bad decision! Still worrying...

(snip)

*I had a 6V4 fail in a Phillips radio a while back but
caught it in time by shear luck as I had a meter on the B+ as a final
check when "zipping up".

(snip)

Roger:

The 6X5 is well known in the vintage radio community for being problematic.
Most of the failures that occur in 6X5s are not heater to cathode, but are
plate to plate or plate to cathode, due to the peculiar construction of the
6X5.

The 6X4, 6V4(EZ80), 6CA4(EZ81) as well as the 6AX5 do not share the same
type of internal construction as the 6X5. *I don't think I have ever seen an
H-K short in these types in the 45 years I've been working on equipment
using them.

I have experienced one... even watched it happen! Was a 6V4 shorting H
to K. See above...

The use of 1N4007s however is another story. *They're rated for 1kV reverse
voltage. *If you use these on a 300-0-300 power transformer, you don't have
enough safety margin (1 kV diode run at 848 volts!!), and have virtually
none at high AC line voltage. *I've seen lots of power transformers taken
out by the misapplication of these buggers, and routinely use two or more
4007s in series to give me a reasonable safety margin. *Stick 1000pF @1kV
across each to help equalize the reverse voltage as well to provide a crude
measure of switching noise suppression.

Best Regards : Doug Bannard, P.Eng

Agreed... use two in series, safer. In the Phillips mentioned radio
the MT was 250-0-250, so that's 707 volts peak across a single 1N4007
- I judged that to be OK.
Cheers,
Roger

[Eeyore[_4_]]

Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.

1960s IIRC. I think from about 1962/3 on.

I just threw out a Ferrograph 4AN ( mono 1/2 track with an additional
1/4 track 2 channel replay head fitted by me in the 'spare position' )
as my house was being totally refurbished and I couldn't keep everything
I'd acquired over the years in a lock-up. Shame but I hadn't used it in
over a decade at least.

It was a close call with a Nagra 3 series too. That was kept.

The old B&K test equipment may go to a collector. I even have a 25dB pot
for the chart recorder as well as the standard 50 dB one. I bought it
all off Neve FWIW, so Rupert himself has probably used it.

Graham

[Ian Bell[_2_]]

Eeyore wrote:
Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.

1960s IIRC. I think from about 1962/3 on.

I just threw out a Ferrograph 4AN ( mono 1/2 track with an additional
1/4 track 2 channel replay head fitted by me in the 'spare position' )
as my house was being totally refurbished and I couldn't keep everything
I'd acquired over the years in a lock-up. Shame but I hadn't used it in
over a decade at least.

It was a close call with a Nagra 3 series too. That was kept.

The old B&K test equipment may go to a collector. I even have a 25dB pot
for the chart recorder as well as the standard 50 dB one. I bought it
all off Neve FWIW, so Rupert himself has probably used it.

Graham


Why on earth did you not mention the Ferrograph here? I would certainly
have had it.

Cheers

Ian

[Eeyore[_4_]]

Ian Bell wrote:
Eeyore wrote:
Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.

1960s IIRC. I think from about 1962/3 on.

I just threw out a Ferrograph 4AN ( mono 1/2 track with an additional
1/4 track 2 channel replay head fitted by me in the 'spare position' )
as my house was being totally refurbished and I couldn't keep everything
I'd acquired over the years in a lock-up. Shame but I hadn't used it in
over a decade at least.

It was a close call with a Nagra 3 series too. That was kept.

The old B&K test equipment may go to a collector. I even have a 25dB pot
for the chart recorder as well as the standard 50 dB one. I bought it
all off Neve FWIW, so Rupert himself has probably used it.

Graham


Why on earth did you not mention the Ferrograph here? I would certainly
have had it.

Cheers

Ian

Sorry ! It was a situation where I was rushed. Anything non-essential
went. Since this isn't a tape group it never occurred to me to mention it.

I'd gladly have let you have it for nought. Sad. It was still almost
'mint' and had had a genuine Ferrograph service back in ~ 1970 !

Graham

[Ian Bell[_2_]]

Eeyore wrote:
Ian Bell wrote:
Eeyore wrote:
Engineer wrote:
Hi, Vacuumlanders,
No recent vintage radio or audio projects to report on, but I did have
a British Ferrograph tape recorder on the bench recently, a series 4,
open-reel, 1950's vintage.

1960s IIRC. I think from about 1962/3 on.

I just threw out a Ferrograph 4AN ( mono 1/2 track with an additional
1/4 track 2 channel replay head fitted by me in the 'spare position' )
as my house was being totally refurbished and I couldn't keep everything
I'd acquired over the years in a lock-up. Shame but I hadn't used it in
over a decade at least.

It was a close call with a Nagra 3 series too. That was kept.

The old B&K test equipment may go to a collector. I even have a 25dB pot
for the chart recorder as well as the standard 50 dB one. I bought it
all off Neve FWIW, so Rupert himself has probably used it.

Graham


Why on earth did you not mention the Ferrograph here? I would
certainly have had it.

Cheers

Ian

Sorry ! It was a situation where I was rushed. Anything non-essential
went. Since this isn't a tape group it never occurred to me to mention it.

I'd gladly have let you have it for nought. Sad. It was still almost
'mint' and had had a genuine Ferrograph service back in ~ 1970 !

Graham

OK, NP, but for future reference I repair and maintain old Ferrographs
and Revoxes and Brenells in the East Anglia region and any old clapped
out ones are always useful for spares. You would be surprised how many
phone calls I get asking for odd Ferrograph parts.

Cheers

Ian