NZ Murphy 23" TV Set - UK Vintage Radio Repair and Restoration Discussion Forum

GLENZ32 · 7th Nov 2011, 8:51 am

Hi guys, well the TV collection has grown yet again...Just the other day I picked up this NZ made Murphy 23 inch B&W Television for a few dollars.

It would be from the mid 1960's at a guess and I quite like the look of this one too.
Hasn't been turned on for about 20 odd years according to the previous owner, they were going to turn it into a fish tank display or something but had sold the house and were about to move house so thankfully the set was saved.

The chassis is basically an AWA 35 Series variant, and pretty certain that it was based on an Australian design. I have another Murphy and two AWA sets with the same chassis as this. From what I've been told they were reliable and performed well. On the back cover it does say 'Manufactured under license from Rank-Bush Murphy Limited'

The deflection yoke plastic shroud that holds the geometry adjust rings has decomposed and the filter caps are leaking and bulging so before I apply any power to this I'll temporarily tack some filter caps in place and then see what happens. May be a while before I get to doing this part but you never know curiosity may get the better of me.

The photos were taken with my new iPod touch as I was curious about the picture quality, not as good as a digital camera but still acceptable.

I've also done a video on You Tube about this, here is the link - http://www.youtube.com/watch?v=8CThn6yz8fE

Enjoy!

Cheers Glen.

mark pirate · 7th Nov 2011, 9:06 am

I noted the Murphy badge on the back appears to have a stag as an emblem, all uk sets had a capital M as the emblem, prewar sets had the M shown within a flag.

Looks to be a well made chassis, should be a nice set when working.

Mark

arjoll · 7th Nov 2011, 9:20 am

Were those '73 date codes in there?

Heatercathodeshort · 7th Nov 2011, 5:17 pm

Very well manufactured. Looks more like a U.K. design from the late 50's plus a mains transformer. They obviously got it right and carried on production with updates required for 'modern' picture tubes and circuitry. Cheers, John.

paulsherwin · 7th Nov 2011, 6:32 pm

All NZ & Aus valve TVs I've come across seem to use mains transformers, rather than being live chassis designs as was the norm here. I think this was something to do with electrical safety regulations but industrial protectionism was probably a factor.

Aussie radios all seem to have transformers too.

jayceebee · 7th Nov 2011, 7:37 pm

Very interesting set, when I looked at picture number three I thought where have I seen those controls before.

Have a look at this youtube clip at 1.38 http://www.youtube.com/watch?v=6jIYa...eature=related

The TV has 8 controls but they look very similar to me.

radioredcat · 7th Nov 2011, 10:08 pm

Well jayceebee you are right and it looks like the first knob is missing.

Nice one .

Andy

GLENZ32 · 7th Nov 2011, 10:25 pm

Good spotting! They sure look like the same controls

Quote:

Originally Posted by jayceebee

Very interesting set, when I looked at picture number three I thought where have I seen those controls before.

Have a look at this youtube clip at 1.38 http://www.youtube.com/watch?v=6jIYa...eature=related

The TV has 8 controls but they look very similar to me.

GLENZ32 · 7th Nov 2011, 10:27 pm

Nah, this set was made in the 1960's...Those transformers are totally
original so I highly doubt it

There are however Tisco service stickers dated 1971 and 1973

Quote:

Originally Posted by arjoll

Were those '73 date codes in there?

GLENZ32 · 7th Nov 2011, 10:32 pm

Thanks John, interesting about your comments regarding the build quality, as this range of chassis is well built and from what I've heard were reliable. Guess I'll find out when I get around to putting some power on it.

Quote:

Originally Posted by Heatercathodeshort

Very well manufactured. Looks more like a U.K. design from the late 50's plus a mains transformer. They obviously got it right and carried on production with updates required for 'modern' picture tubes and circuitry. Cheers, John.

GLENZ32 · 7th Nov 2011, 10:34 pm

Hi Paul, yes you are correct, most of our TV's were isolated apart from Philips as they were like your English counterparts - live chassis and series strung filament chain.

Quote:

Originally Posted by paulsherwin

All NZ & Aus valve TVs I've come across seem to use mains transformers, rather than being live chassis designs as was the norm here. I think this was something to do with electrical safety regulations but industrial protectionism was probably a factor.

Aussie radios all seem to have transformers too.

jayceebee · 8th Nov 2011, 10:48 pm

Does the set have a Fireball tuner

Sorry couldn't resist it.

Billy T · 11th Nov 2011, 10:16 am

Quote:

Originally Posted by paulsherwin

All NZ & Aus valve TVs I've come across seem to use mains transformers, rather than being live chassis designs as was the norm here. I think this was something to do with electrical safety regulations but industrial protectionism was probably a factor.

It was not a regulatory requirement Paul, and I don't think protectionism entered the equation either, but New Zealand and Australia share a common and conservative approach to electrical issues which is why so many radios and later, TVs had mains transformers. Our climate may also have been a factor because AC-DC sets always seemed to run at higher temperatures (probably because of the need for dropper resistors) but the main benefit in my experience was significantly enhanced reliability. For a time I was a senior tech in the biggest TV workshop in NZ (TISCO Auckland) and the bulk of our workload was the transformerless stuff.

To this day I dislike transformerless radios and there is only one in my collection (a Philips) and that is there only because it belonged to an old lady I looked after for many years and I kept it after she passed away. We are still using the National TV I bought for her when she moved into a Rest Home and needed a smaller set. It has been in daily use for nearly 30 years now, has never had the back off, and is still going strong. It has a transformer not an SMPS.

Cheers

Billy

GLENZ32 · 20th Dec 2011, 10:12 am

Hi, here is a bit of an update on this TV... I got curious and started poking around the chassis a bit, decided to temporarily put in some 100uf filter caps in the power supply and change the boost caps just to be safe and attempted to fire the set up.

Using the variac I wound the voltage up I could hear things rustling and noises from the speaker, then the vertical kicked in, so I wound the variac up a bit more and there was an odd squeal from the LOPT and then the 1B3GT lit up a pretty purple inside! Hmm...me thinks that valve's a bit gassy so I put another good one in and powered on again and this time we had EHT but no picture or even a raster.

Checked voltages around the video stages, all appeared to be ok there and the cathode volts to the crt was within spec. I turned the set off to see if anything would happen and as the EHT collapsed there was a small bright image on the screen....ah-ha... Seemed like the CRT was being cut off. I didn't get much further that night as was very tired, but chose to contact BillyT at a later stage and run it past him.

BillyT advised to check the grid voltage and as the circuit stated grid volts should have been at least 80-90 volts on pin 2 of the crt which of course varies with brightness. Mine measured only 40 volts on the grid... we have a problem here!
In the brightness control area were a couple of resistors in series with the pot and a 100k to ground which checked ok but there also were some 0.1uf coupling caps which turned out to be leaky, replaced them and I now get a picture although its lacks width and the verticals all up the creek, but at least the TV is now functioning and its producing sound and a picture of sorts, so a good start so far.

My next move is to investigate the lack of width, the picture is not very bright and the EHT is lower than it should be at full mains voltage so will look into that and then will sort out the vertical which may improve when the width is sorted.
There are a lot of wax paper caps in this one so replacing those will only improve things no doubt and I can bet there are a few resistors that have drifted way off also.

That's all for now. Stay tuned...

Cheers Glen.

AndrewM · 22nd Dec 2011, 10:43 pm

It is looking promising and it's good to see all the important parts are working.
Once all those paper capacitors have been replaced the set will be much happier! Despite being a good brand, after 50 years, those Ducon capacitors are nearly always leaky.

GLENZ32 · 23rd Dec 2011, 11:28 am

Thanks Andrew, those Ducon capacitors will more than likely be causing all the grief with this chassis. This will be a long long project and I have three more sets using the same chassis as well, so I'll be well seasoned when I get to the third one whenever that will be! Sometimes its hard to stay focused on one set, especially when others keep turning up

Cheers
Glen

Brigham · 23rd Dec 2011, 5:18 pm

Would it be right to think that DC mains supply was less common in Aus/NZ at this time?

Synchrodyne · 24th Dec 2011, 3:02 am

DC mains would have been scarce to non-existent in NZ by the 1960s. See: https://www.vintage-radio.net/forum/...ad.php?t=62608.

Even so, the use of double-wound mains transformers for NZ radio and TV receivers, although not a universal (so as to speak) practice, was considered to be the norm. I imagine that was less to do with available mains supplies than it was considered to be the “right and proper” thing to do. I wouldn’t like to have to argue the negative on that proposition.

As far as I know Australia was not much different to NZ in that regard, although an excerpt from Davies, attached, suggests that double-wound main transformers were mandatory in some parts.

Cheers,

Billy T · 24th Dec 2011, 8:47 am

Quote:

Originally Posted by Synchrodyne

DC mains would have been scarce to non-existent in NZ by the 1960s. Cheers,

Since TV did not arrive here until the mid 1960's, our National grid was solidly AC and DC mains were never used for domestic supply in NZ in that era, though historically there were some private and/or local DC installations and one industrial/commercial supply in Auckland that ran until the late 1950's. No TV sets were ever run on DC, except perhaps for isolated instances of privately operated generation facilities not connected to the National Grid.

Strictly speaking our transformerless TV sets were AC models rather than AC-DC, though if I look through my historical circuits manual there are definitely plenty of examples of AC/DC functionality. A number of early sets were based on transformerless AC/DC designs but I doubt that they would have been suitable for straight DC operation without some modificiation.

Cheers

Billy

Maarten · 24th Dec 2011, 7:36 pm

In later models, I seem to remember the KT3 chassis which was also sold in Australia (KL9 or soething like that??), some sets had a single diode rectifier while others used a bridge. The requirement for symmetrical loading may have had something to do with that. Both versions were non-insulated (though having an smps not exactly transformerless).

7th Nov 2011, 8:51 am	#1
GLENZ32 Hexode Join Date: Apr 2008 Location: Wellington, New Zealand Posts: 289	NZ Murphy 23" TV Set Hi guys, well the TV collection has grown yet again...Just the other day I picked up this NZ made Murphy 23 inch B&W Television for a few dollars. It would be from the mid 1960's at a guess and I quite like the look of this one too. Hasn't been turned on for about 20 odd years according to the previous owner, they were going to turn it into a fish tank display or something but had sold the house and were about to move house so thankfully the set was saved. The chassis is basically an AWA 35 Series variant, and pretty certain that it was based on an Australian design. I have another Murphy and two AWA sets with the same chassis as this. From what I've been told they were reliable and performed well. On the back cover it does say 'Manufactured under license from Rank-Bush Murphy Limited' The deflection yoke plastic shroud that holds the geometry adjust rings has decomposed and the filter caps are leaking and bulging so before I apply any power to this I'll temporarily tack some filter caps in place and then see what happens. May be a while before I get to doing this part but you never know curiosity may get the better of me. The photos were taken with my new iPod touch as I was curious about the picture quality, not as good as a digital camera but still acceptable. I've also done a video on You Tube about this, here is the link - http://www.youtube.com/watch?v=8CThn6yz8fE Enjoy! Cheers Glen. Attached Thumbnails __________________ Visit my Vintage TV & Radio Page - http://nzvintagetvradio.blogspot.com/ Last edited by GLENZ32; 7th Nov 2011 at 8:57 am.

7th Nov 2011, 9:06 am	#2
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: NZ Murphy 23" TV Set I noted the Murphy badge on the back appears to have a stag as an emblem, all uk sets had a capital M as the emblem, prewar sets had the M shown within a flag. Looks to be a well made chassis, should be a nice set when working. Mark

7th Nov 2011, 9:20 am	#3
arjoll Dekatron Join Date: May 2006 Location: Invercargill, New Zealand Posts: 3,458	Re: NZ Murphy 23" TV Set Were those '73 date codes in there?

7th Nov 2011, 5:17 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: NZ Murphy 23" TV Set Very well manufactured. Looks more like a U.K. design from the late 50's plus a mains transformer. They obviously got it right and carried on production with updates required for 'modern' picture tubes and circuitry. Cheers, John.

7th Nov 2011, 6:32 pm	#5
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,959	Re: NZ Murphy 23" TV Set All NZ & Aus valve TVs I've come across seem to use mains transformers, rather than being live chassis designs as was the norm here. I think this was something to do with electrical safety regulations but industrial protectionism was probably a factor. Aussie radios all seem to have transformers too.

7th Nov 2011, 7:37 pm	#6
jayceebee Heptode Join Date: Jun 2007 Location: Durham, County Durham, UK. Posts: 640	Re: NZ Murphy 23" TV Set Very interesting set, when I looked at picture number three I thought where have I seen those controls before. Have a look at this youtube clip at 1.38 http://www.youtube.com/watch?v=6jIYa...eature=related The TV has 8 controls but they look very similar to me.

7th Nov 2011, 10:08 pm	#7
radioredcat Hexode Join Date: Apr 2009 Location: Billinge, Wigan, UK. Posts: 492	Re: NZ Murphy 23" TV Set Well jayceebee you are right and it looks like the first knob is missing. Nice one . Andy __________________ http://www.youtube.com/user/radioredcat Last edited by Brian R Pateman; 7th Nov 2011 at 10:41 pm. Reason: Unnecessary quote removed.

8th Nov 2011, 10:48 pm	#12
jayceebee Heptode Join Date: Jun 2007 Location: Durham, County Durham, UK. Posts: 640	Re: NZ Murphy 23" TV Set Does the set have a Fireball tuner Sorry couldn't resist it.

20th Dec 2011, 10:12 am	#14
GLENZ32 Hexode Join Date: Apr 2008 Location: Wellington, New Zealand Posts: 289	Re: NZ Murphy 23" TV Set Hi, here is a bit of an update on this TV... I got curious and started poking around the chassis a bit, decided to temporarily put in some 100uf filter caps in the power supply and change the boost caps just to be safe and attempted to fire the set up. Using the variac I wound the voltage up I could hear things rustling and noises from the speaker, then the vertical kicked in, so I wound the variac up a bit more and there was an odd squeal from the LOPT and then the 1B3GT lit up a pretty purple inside! Hmm...me thinks that valve's a bit gassy so I put another good one in and powered on again and this time we had EHT but no picture or even a raster. Checked voltages around the video stages, all appeared to be ok there and the cathode volts to the crt was within spec. I turned the set off to see if anything would happen and as the EHT collapsed there was a small bright image on the screen....ah-ha... Seemed like the CRT was being cut off. I didn't get much further that night as was very tired, but chose to contact BillyT at a later stage and run it past him. BillyT advised to check the grid voltage and as the circuit stated grid volts should have been at least 80-90 volts on pin 2 of the crt which of course varies with brightness. Mine measured only 40 volts on the grid... we have a problem here! In the brightness control area were a couple of resistors in series with the pot and a 100k to ground which checked ok but there also were some 0.1uf coupling caps which turned out to be leaky, replaced them and I now get a picture although its lacks width and the verticals all up the creek, but at least the TV is now functioning and its producing sound and a picture of sorts, so a good start so far. My next move is to investigate the lack of width, the picture is not very bright and the EHT is lower than it should be at full mains voltage so will look into that and then will sort out the vertical which may improve when the width is sorted. There are a lot of wax paper caps in this one so replacing those will only improve things no doubt and I can bet there are a few resistors that have drifted way off also. That's all for now. Stay tuned... Cheers Glen. Attached Thumbnails __________________ Visit my Vintage TV & Radio Page - http://nzvintagetvradio.blogspot.com/ Last edited by GLENZ32; 20th Dec 2011 at 10:33 am.

22nd Dec 2011, 10:43 pm	#15
AndrewM Pentode Join Date: Apr 2009 Location: Melbourne, Australia Posts: 115	Re: NZ Murphy 23" TV Set It is looking promising and it's good to see all the important parts are working. Once all those paper capacitors have been replaced the set will be much happier! Despite being a good brand, after 50 years, those Ducon capacitors are nearly always leaky.

23rd Dec 2011, 11:28 am	#16
GLENZ32 Hexode Join Date: Apr 2008 Location: Wellington, New Zealand Posts: 289	Re: NZ Murphy 23" TV Set Thanks Andrew, those Ducon capacitors will more than likely be causing all the grief with this chassis. This will be a long long project and I have three more sets using the same chassis as well, so I'll be well seasoned when I get to the third one whenever that will be! Sometimes its hard to stay focused on one set, especially when others keep turning up Cheers Glen __________________ Visit my Vintage TV & Radio Page - http://nzvintagetvradio.blogspot.com/

23rd Dec 2011, 5:18 pm	#17
Brigham Octode Join Date: Mar 2006 Location: Co. Durham, UK. Posts: 1,117	Re: NZ Murphy 23" TV Set Would it be right to think that DC mains supply was less common in Aus/NZ at this time?

24th Dec 2011, 3:02 am	#18
Synchrodyne Nonode Join Date: Jan 2009 Location: Papamoa Beach, Bay of Plenty, New Zealand Posts: 2,944	Re: NZ Murphy 23" TV Set DC mains would have been scarce to non-existent in NZ by the 1960s. See: https://www.vintage-radio.net/forum/...ad.php?t=62608. Even so, the use of double-wound mains transformers for NZ radio and TV receivers, although not a universal (so as to speak) practice, was considered to be the norm. I imagine that was less to do with available mains supplies than it was considered to be the “right and proper” thing to do. I wouldn’t like to have to argue the negative on that proposition. As far as I know Australia was not much different to NZ in that regard, although an excerpt from Davies, attached, suggests that double-wound main transformers were mandatory in some parts. Cheers, Attached Thumbnails

24th Dec 2011, 7:36 pm	#20
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,203	Re: NZ Murphy 23" TV Set In later models, I seem to remember the KT3 chassis which was also sold in Australia (KL9 or soething like that??), some sets had a single diode rectifier while others used a bridge. The requirement for symmetrical loading may have had something to do with that. Both versions were non-insulated (though having an smps not exactly transformerless).