Tube Tester 1-177B - UK Vintage Radio Repair and Restoration Discussion Forum

Wendymott · 27th Nov 2015, 6:54 pm

Hi Peeps. As some of you may have seen in the wanted area, My Moving coil meter went O/C. That has now been fixed with an external meter, however I am having difficulty getting a decent emission reading for the 6AM6 / EF91 / Z77. As it is not listed in the data book, I wonder if any of you out there have the switch settings. At present I am using A 8, B 5, L set to

? and R set to ""0". The emissions readings are way down in the red area. The socket I am using is the B7G (K) as used for other similar types.
If Ed Dinning sees this he may have some data.
I attach photo's of the "get me working mod"

Ed_Dinning · 27th Nov 2015, 10:38 pm

Hi Wendy, worthy of the Royal Engineers. "Adopt, Adapt, Modify"

Ed

Wendymott · 28th Nov 2015, 12:40 am

Hi Ed.
I was quite pleased how the meter scaling turned out. I used my PCB design package, as it has good X and Y position pointer. The only problem with my cad package it that you cannot "Free" Rotate text, only 90 degree steps. You can "free" rotate components but not text.
Now I know I will get lots of recommendations of other drawing packages, but it takes time to learn them, and I am reasonably happy with what I have.

Chaparal · 28th Nov 2015, 10:10 am

Data for 6AM6
--------------
Volt - 6,3 V
Heat - FIL = 4
Heat - FIL = 3
Grid - G = 1
Plate - P = 5
Screen - SC = 7
Cath - K = 2
Suppr - K = 6
L = 65
R = 9
Press - AMPL. TEST
Aver. Mutal Cond. - 3000

Peter

Wendymott · 28th Nov 2015, 4:10 pm

Hi Peter. Many thanks. I will recheck.

Wendymott · 3rd Dec 2015, 11:24 am

Hi... due to the possibility of "Oscillation" with high gain valves such as the EF93/6BE6, I thought that de coupling the valve pins may be of order, but to where ? Say Anode and Grid and screen, with 10NF, but to where ?? Chassis or cathode ?
What do the modern testers do in this context please ?

frankmcvey · 3rd Dec 2015, 12:56 pm

Hi, Wendy,

A number of testers, such as the Mullard HVST, use ferrite beads slipped over the valveholder wiring near to the valveholder itself to prevent parasitic oscillation. Easy to fit, you can obtain different sizes for different wire gauges and they're not too dear.

Write-up here.

Obtainable here.

Cheers,

Frank

frankmcvey · 3rd Dec 2015, 4:14 pm

Oops. Should have read:

Obtainable here:

Wendymott · 3rd Dec 2015, 11:19 pm

Hi Frank.... Thanks mucho I will try asap... but still fixing my eddy 888..

27th Nov 2015, 6:54 pm	#1
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Tube Tester 1-177B Hi Peeps. As some of you may have seen in the wanted area, My Moving coil meter went O/C. That has now been fixed with an external meter, however I am having difficulty getting a decent emission reading for the 6AM6 / EF91 / Z77. As it is not listed in the data book, I wonder if any of you out there have the switch settings. At present I am using A 8, B 5, L set to ? and R set to ""0". The emissions readings are way down in the red area. The socket I am using is the B7G (K) as used for other similar types. If Ed Dinning sees this he may have some data. I attach photo's of the "get me working mod" Attached Thumbnails __________________ Should get out more. Regards Wendy G8BZY Last edited by Wendymott; 27th Nov 2015 at 6:58 pm. Reason: Additional data

27th Nov 2015, 10:38 pm	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Tube Tester 1-177B Hi Wendy, worthy of the Royal Engineers. "Adopt, Adapt, Modify" Ed

28th Nov 2015, 12:40 am	#3
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: Tube Tester 1-177B Hi Ed. I was quite pleased how the meter scaling turned out. I used my PCB design package, as it has good X and Y position pointer. The only problem with my cad package it that you cannot "Free" Rotate text, only 90 degree steps. You can "free" rotate components but not text. Now I know I will get lots of recommendations of other drawing packages, but it takes time to learn them, and I am reasonably happy with what I have. __________________ Should get out more. Regards Wendy G8BZY

28th Nov 2015, 10:10 am	#4
Chaparal Hexode Join Date: Apr 2007 Location: Wiesbaden, Germany Posts: 333	Re: Tube Tester 1-177B Data for 6AM6 -------------- Volt - 6,3 V Heat - FIL = 4 Heat - FIL = 3 Grid - G = 1 Plate - P = 5 Screen - SC = 7 Cath - K = 2 Suppr - K = 6 L = 65 R = 9 Press - AMPL. TEST Aver. Mutal Cond. - 3000 Peter

28th Nov 2015, 4:10 pm	#5
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: Tube Tester 1-177B Hi Peter. Many thanks. I will recheck. __________________ Should get out more. Regards Wendy G8BZY

3rd Dec 2015, 11:24 am	#6
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: Tube Tester 1-177B Hi... due to the possibility of "Oscillation" with high gain valves such as the EF93/6BE6, I thought that de coupling the valve pins may be of order, but to where ? Say Anode and Grid and screen, with 10NF, but to where ?? Chassis or cathode ? What do the modern testers do in this context please ? __________________ Should get out more. Regards Wendy G8BZY

3rd Dec 2015, 12:56 pm	#7
frankmcvey Rest in Peace Join Date: Jan 2015 Location: Cottesmore, East Midlands, UK. Posts: 858	Re: Tube Tester 1-177B Hi, Wendy, A number of testers, such as the Mullard HVST, use ferrite beads slipped over the valveholder wiring near to the valveholder itself to prevent parasitic oscillation. Easy to fit, you can obtain different sizes for different wire gauges and they're not too dear. Write-up here. Obtainable here. Cheers, Frank

3rd Dec 2015, 4:14 pm	#8
frankmcvey Rest in Peace Join Date: Jan 2015 Location: Cottesmore, East Midlands, UK. Posts: 858	Re: Tube Tester 1-177B Oops. Should have read: Obtainable here:

3rd Dec 2015, 11:19 pm	#9
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: Tube Tester 1-177B Hi Frank.... Thanks mucho I will try asap... but still fixing my eddy 888.. __________________ Should get out more. Regards Wendy G8BZY