Murphy V230: A 12" portable TV set. - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 31st Jan 2007, 9:42 pm

This is my latest restoration project. The Murphy V230 is a 12 inch CRT set of 1955 vintage. The construction quality of this set is of a very high standard, allways a feature of Murphy TV and radio sets.

The turret tuner employed in this set is the four position unit which was fitted to later sets including the model V310. Murphy designers believed that there was no point fitting a 13 channel unit when in most cases only two TV services were in available. The third and fourth positions could take care of any areas where the set could receive two ITV services.

The valves used in this set are the Mazda 0.1 and 0.2amp heater series, the two heater chains merge to supply the 0.3 amp CRT and tuner valves.
The set will operate on AC and DC mains supplies.

The set is presently connected to the variac. I will report how things progress.

DFWB

wiwior · 1st Feb 2007, 12:22 am

Hi David,

In my opinion no need to plug though a variac; last time I powered it seems work correctly, except it was a problem of reception.

all the best

wilfrid

FERNSEH · 1st Feb 2007, 2:11 am

Hi Wilfrid,
It's all good news, the set is working but the set requires channel B1 coils to operate on the existing 405 modulators.

Two sections on the tapped heater ballast resistor were found to be OC. I've soldered two 33ohm resistors across the faulty sections and now I have a bright raster and some noise from the loudspeaker.
I have a Murphy V310 upstairs, there is just a chance that the set might be equiped with channel B1 coils.

The HT voltage is a bit low, only 168 volts. This may be correct, I'll check the circuit diagram.

The tuner valves apart, all the valves are special Mazda (England) types and there are no common European types as equivalents. For example the HT rectifier (redresseur) is an U801 and has four diodes.
The line output valve is a 20P4, similar to the 30P4/PL36/30P19/PL302 except it has a 0.2amp filament.

To sum up, if I can find the channel B1 coils for the tuner the set will be displaying pictures very soon.

DFWB.

chipp1968 · 1st Feb 2007, 10:22 am

Is this the set that people pinch the tubes from for older sets ?

FERNSEH · 1st Feb 2007, 11:28 am

Quote:

Originally Posted by chipp1968

Is this the set that people pinch the tubes from for older sets ?

'fraid so. The Mazda CRM124 employed in the V230 could be used as a replacement for the MW31-16/74. The Mazda tube has a tetrode gun and the heater is 12.6 volts @ 0.3amp. OK for series heater chains.

DFWB.

Sean Williams · 1st Feb 2007, 8:25 pm

Was this a recent acquisition David? - I saw one at Wetwood last weekend, but was beaten in the rush on bidding......

Cheers
Sean

FERNSEH · 1st Feb 2007, 9:30 pm

Hi Sean,
The V230 actually belongs to Forum member Wilfrid (wiwior) and I will be taking it back to France in April. Hopefully the Philips TF384 will be ready by then.

I glad to hear about the rush by many at Wetwood to acquire the V230 set. Only one concern, was the person who won the set interested in restoring it, or was he only after the CRT?

Another Murphy portable TV comes to mind, the V350. This 14" set was made in 1958 and employed the Mazda CME141 electrostatic focus CRT.
Well worth looking out for one.
DFWB.

FERNSEH · 12th Jun 2007, 10:40 pm

I've been on the look out for the channel 1 coils for this set. No luck so I've modified the existing channel 5 coils to operate on channel 4.

My first idea was to wind extra turns on the Ch5 coils so that the set would work on Ch1. That turned out to be a waste of time.

The tube is a bit soft, the focus could be better but I'm sure the contrast could be improved if the video amplifier stage is is examined.

DFWB.

jim_beacon · 13th Jun 2007, 12:03 am

The construction reminds me of my Defiant transportable. You have to remove the tube to work on the chassis - I learnt the hard way that you should check all the resistors when you change the caps......

Jim.

31st Jan 2007, 9:42 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Murphy V230: A 12" portable TV set. This is my latest restoration project. The Murphy V230 is a 12 inch CRT set of 1955 vintage. The construction quality of this set is of a very high standard, allways a feature of Murphy TV and radio sets. The turret tuner employed in this set is the four position unit which was fitted to later sets including the model V310. Murphy designers believed that there was no point fitting a 13 channel unit when in most cases only two TV services were in available. The third and fourth positions could take care of any areas where the set could receive two ITV services. The valves used in this set are the Mazda 0.1 and 0.2amp heater series, the two heater chains merge to supply the 0.3 amp CRT and tuner valves. The set will operate on AC and DC mains supplies. The set is presently connected to the variac. I will report how things progress. DFWB Attached Thumbnails

1st Feb 2007, 12:22 am	#2
wiwior Tetrode Join Date: Apr 2006 Location: 60510 la Neuville en Hez France Posts: 71	Re: Murphy V230: A 12" portable TV set. Hi David, In my opinion no need to plug though a variac; last time I powered it seems work correctly, except it was a problem of reception. all the best wilfrid Attached Thumbnails

1st Feb 2007, 2:11 am	#3
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Murphy V230: A 12" portable TV set. Hi Wilfrid, It's all good news, the set is working but the set requires channel B1 coils to operate on the existing 405 modulators. Two sections on the tapped heater ballast resistor were found to be OC. I've soldered two 33ohm resistors across the faulty sections and now I have a bright raster and some noise from the loudspeaker. I have a Murphy V310 upstairs, there is just a chance that the set might be equiped with channel B1 coils. The HT voltage is a bit low, only 168 volts. This may be correct, I'll check the circuit diagram. The tuner valves apart, all the valves are special Mazda (England) types and there are no common European types as equivalents. For example the HT rectifier (redresseur) is an U801 and has four diodes. The line output valve is a 20P4, similar to the 30P4/PL36/30P19/PL302 except it has a 0.2amp filament. To sum up, if I can find the channel B1 coils for the tuner the set will be displaying pictures very soon. DFWB.

1st Feb 2007, 10:22 am	#4
chipp1968 Rest in Peace Join Date: Jul 2006 Location: Somerset, UK. Posts: 2,356	Re: Murphy V230: A 12" portable TV set. Is this the set that people pinch the tubes from for older sets ?

1st Feb 2007, 8:25 pm	#6
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	Re: Murphy V230: A 12" portable TV set. Was this a recent acquisition David? - I saw one at Wetwood last weekend, but was beaten in the rush on bidding...... Cheers Sean __________________ Engineers make things work and have spare bits when finished

1st Feb 2007, 9:30 pm	#7
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Murphy V230: A 12" portable TV set. Hi Sean, The V230 actually belongs to Forum member Wilfrid (wiwior) and I will be taking it back to France in April. Hopefully the Philips TF384 will be ready by then. I glad to hear about the rush by many at Wetwood to acquire the V230 set. Only one concern, was the person who won the set interested in restoring it, or was he only after the CRT? Another Murphy portable TV comes to mind, the V350. This 14" set was made in 1958 and employed the Mazda CME141 electrostatic focus CRT. Well worth looking out for one. DFWB.

12th Jun 2007, 10:40 pm	#8
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Murphy V230: A 12" portable TV set. I've been on the look out for the channel 1 coils for this set. No luck so I've modified the existing channel 5 coils to operate on channel 4. My first idea was to wind extra turns on the Ch5 coils so that the set would work on Ch1. That turned out to be a waste of time. The tube is a bit soft, the focus could be better but I'm sure the contrast could be improved if the video amplifier stage is is examined. DFWB. Attached Thumbnails

13th Jun 2007, 12:03 am	#9
jim_beacon Retired Dormant Member Join Date: Mar 2003 Location: Bishop's Waltham, Hants, UK. Posts: 939	Re: Murphy V230: A 12" portable TV set. The construction reminds me of my Defiant transportable. You have to remove the tube to work on the chassis - I learnt the hard way that you should check all the resistors when you change the caps...... Jim.