Early Roberts - M4Q - UK Vintage Radio Repair and Restoration Discussion Forum

simonsradio · 22nd Sep 2007, 10:14 pm

Can anyone help by telling me the valve line up of a Roberts M4Q? I have one with QP22B, PM1HF,PM2HL and one missing valve. This set, which I have just acquired, seems to have received some inexpert attention wich I plan to put to rights so if anyone has any further information I'd be grateful for that too - such as HT and grid voltages?

Paul_RK · 22nd Sep 2007, 11:56 pm

There's an engaging article on early Roberts sets by the late Geoffrey Dixon-Nuttall in the Spring 2007 'Radiophile', including circuit and chassis layout for the M4Q drawn by himself: he comments that Roberts at this time seem not to have got around to issuing service sheets. At least in his set, the valves were an SP2, two PM2HL and a QP22B. Neither his article nor the operating instructions that came with my M4Q (available at http://groups.yahoo.com/group/robertsradiogroup/ ) gives the HT voltage, which I'd guess would be 108 or 120: '-6' is pencilled in on his diagram as the grid bias voltage. I've yet to get my own set up and running.

Regards,
Paul

batterymaker1 · 23rd Sep 2007, 4:40 am

Just pulled the data from a 1949 Exide catalog--it uses an RJ3 2v gel cell and an H1152 105 and 3v HT battery.

Can't find a cross to Ever Ready. Later catalogs have neither battery listed anymore.

Bill

simonsradio · 23rd Sep 2007, 10:20 am

Thank you both - and for the link to the Yahoo forum that I hadn't discovered.
Simon.

simonsradio · 23rd Sep 2007, 3:56 pm

Paul, I'm struggling to find the operating instructions that you mentioned, on the yahoo forum. Can you point me in the right direction? Thanks. Simon.

morecider · 23rd Sep 2007, 8:34 pm

Hi
Just found a copy of a roberts M4Q blue print showing the following voltages.
HT+ 100v
LT 2v
GRID- -7.5v
The valve line up is SP2 2HL 2HL QP22B

Pete

simonsradio · 24th Sep 2007, 1:46 pm

Pete, thats fantastic, thanks. Is there any chance of a copy of the blueprint (I'll pay any costs)?
Regards
Simon

Paul_RK · 25th Sep 2007, 7:46 pm

Quote:

Originally Posted by simonsradio

Paul, I'm struggling to find the operating instructions that you mentioned, on the yahoo forum. Can you point me in the right direction? Thanks. Simon.

Click on "Photos" on the left of the homepage, and then at bottom left among the albums there's one called "M4Q documentation". The instructions aren't exactly thorough, but that's all the new user received.

Paul

morecider · 25th Sep 2007, 9:39 pm

Hi Simon
I have PM you my contact details
Regards
Pete

simonsradio · 27th Sep 2007, 10:34 pm

Thank you all. I now have just to track down an SP2 and then I can start to try to get this old set going. Batterymaker1, I don't suppose you can point me to scans of the casings for these batteries....?

batterymaker1 · 29th Sep 2007, 1:26 pm

Unfortunately, no. All I have are dimensions.

simonsradio · 30th Sep 2007, 7:46 pm

Batterymaker1, thanks anyway. Could you post the dimensions for me? Thanks.

batterymaker1 · 2nd Oct 2007, 2:15 am

Hmmm, thought I posted this earlier this morning. Must've not taken.

I don't have the measurements for the wet cell--the catalog names the model, but neglects to add any wet cell data. It's probably standard size, something on the order of 2 or 3" square x 5" tall.

BUT, I can tell you that the H.1152 measures 10"x5"x3", according to the 1949 Exide catalog.

Bill

simonsradio · 2nd Oct 2007, 10:54 am

Thanks - every little piece of data helps!

22nd Sep 2007, 10:14 pm	#1
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Early Roberts - M4Q Can anyone help by telling me the valve line up of a Roberts M4Q? I have one with QP22B, PM1HF,PM2HL and one missing valve. This set, which I have just acquired, seems to have received some inexpert attention wich I plan to put to rights so if anyone has any further information I'd be grateful for that too - such as HT and grid voltages?

22nd Sep 2007, 11:56 pm	#2
Paul_RK Dekatron Join Date: Nov 2003 Location: Fakenham, Norfolk, UK. Posts: 4,259	Re: Early Roberts - M4Q There's an engaging article on early Roberts sets by the late Geoffrey Dixon-Nuttall in the Spring 2007 'Radiophile', including circuit and chassis layout for the M4Q drawn by himself: he comments that Roberts at this time seem not to have got around to issuing service sheets. At least in his set, the valves were an SP2, two PM2HL and a QP22B. Neither his article nor the operating instructions that came with my M4Q (available at http://groups.yahoo.com/group/robertsradiogroup/ ) gives the HT voltage, which I'd guess would be 108 or 120: '-6' is pencilled in on his diagram as the grid bias voltage. I've yet to get my own set up and running. Regards, Paul

23rd Sep 2007, 4:40 am	#3
batterymaker1 Heptode Join Date: Apr 2006 Location: Indianapolis, Indiana, USA. Posts: 674	Re: Early Roberts - M4Q Just pulled the data from a 1949 Exide catalog--it uses an RJ3 2v gel cell and an H1152 105 and 3v HT battery. Can't find a cross to Ever Ready. Later catalogs have neither battery listed anymore. Bill __________________ Just playing with high voltage....

23rd Sep 2007, 10:20 am	#4
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Thank you both - and for the link to the Yahoo forum that I hadn't discovered. Simon.

23rd Sep 2007, 3:56 pm	#5
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Paul, I'm struggling to find the operating instructions that you mentioned, on the yahoo forum. Can you point me in the right direction? Thanks. Simon.

23rd Sep 2007, 8:34 pm	#6
morecider Retired Dormant Member Join Date: May 2007 Location: Exeter, Devon, UK. Posts: 30	Re: Early Roberts - M4Q Hi Just found a copy of a roberts M4Q blue print showing the following voltages. HT+ 100v LT 2v GRID- -7.5v The valve line up is SP2 2HL 2HL QP22B Pete

24th Sep 2007, 1:46 pm	#7
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Pete, thats fantastic, thanks. Is there any chance of a copy of the blueprint (I'll pay any costs)? Regards Simon

25th Sep 2007, 9:39 pm	#9
morecider Retired Dormant Member Join Date: May 2007 Location: Exeter, Devon, UK. Posts: 30	Re: Early Roberts - M4Q Hi Simon I have PM you my contact details Regards Pete

27th Sep 2007, 10:34 pm	#10
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Thank you all. I now have just to track down an SP2 and then I can start to try to get this old set going. Batterymaker1, I don't suppose you can point me to scans of the casings for these batteries....? Last edited by simonsradio; 27th Sep 2007 at 10:35 pm. Reason: Incorrect use of smilie

29th Sep 2007, 1:26 pm	#11
batterymaker1 Heptode Join Date: Apr 2006 Location: Indianapolis, Indiana, USA. Posts: 674	Re: Early Roberts - M4Q Unfortunately, no. All I have are dimensions. __________________ Just playing with high voltage....

30th Sep 2007, 7:46 pm	#12
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Batterymaker1, thanks anyway. Could you post the dimensions for me? Thanks.

2nd Oct 2007, 2:15 am	#13
batterymaker1 Heptode Join Date: Apr 2006 Location: Indianapolis, Indiana, USA. Posts: 674	Re: Early Roberts - M4Q Hmmm, thought I posted this earlier this morning. Must've not taken. I don't have the measurements for the wet cell--the catalog names the model, but neglects to add any wet cell data. It's probably standard size, something on the order of 2 or 3" square x 5" tall. BUT, I can tell you that the H.1152 measures 10"x5"x3", according to the 1949 Exide catalog. Bill __________________ Just playing with high voltage....

2nd Oct 2007, 10:54 am	#14
simonsradio Tetrode Join Date: Jul 2007 Location: Chippenham, Wiltshire, UK. Posts: 90	Re: Early Roberts - M4Q Thanks - every little piece of data helps!