ULTRA TIGER TRF tuning bother possibly ?? - UK Vintage Radio Repair and Restoration Discussion Forum

lloydwells · 4th Apr 2020, 5:13 pm

I bought a 1932/33 ultra tiger console about a month ago the set was a complete wreck and is now sort of operational this one uses an AC/SGVM , AC/SG and AC/PEN along with a UU2 anyway the set will tune with good volume through half of the scale then volume on tuned stations on the other half drops to next to nothing with little to no background noise between stations either it does the same thing on both MW & LW everything seems to be withing spec all the Caps have been changed. And I'm at a bit of a loss with it.

This is the earlier type of tiger three valves plus rectifier not the next year's four valve version.

Mr 1936 · 4th Apr 2020, 7:33 pm

I guess you may have checked already, but the two things I can think of are one of the tuning capacitor vanes shorting; or bandpass top coupling capacitor very low in value giving insufficient coupling at the LF end.

lloydwells · 4th Apr 2020, 9:14 pm

Ok the tuning cap isn't shorting that was my first port of call on the rest of you post I'm gonna have to say nope didn't understand a bit of it please explain.

PJL · 4th Apr 2020, 11:28 pm

Try cleaning the earthing contacts to the tuning condensor spindle. Is the weak end with the vanes closed or open?

lloydwells · 5th Apr 2020, 10:34 am

With it closed its weak

vinrads · 5th Apr 2020, 12:19 pm

Hi is there any corrosion where the vanes are fixed to the spindle ,also measure the capacitance when fully closed , Mick.

Mr 1936 · 5th Apr 2020, 1:14 pm

Hi. The top coupling capacitor is the series one between the two tuned circuits in the RF front end. It will have quite a small value.

lloydwells · 5th Apr 2020, 1:32 pm

Ok I have taken the tuning cap off stripped it cleaned it regreased the bearings and put it back together, this is a 3 gang condenser I've got 437, 440 and 445 pf whic isn't far from the 435pf on the diagram I'm going to give the chassis a quick tart up while it's off and I'll put it back on this afternoon.

lloydwells · 5th Apr 2020, 8:52 pm

Well that's it all back together it's quite a bit better but still nowhere near perfect

D.Finney · 6th Apr 2020, 12:37 pm

AS a matter of interest your set is identical to one I bought C.1976 from a dealer in Wigan, it worked well at the time; I gave it away about 20 years ago due to lack of space.

4th Apr 2020, 5:13 pm	#1
lloydwells Heptode Join Date: Aug 2016 Location: Dumfries, Scotland, UK. Posts: 550	ULTRA TIGER TRF tuning bother possibly ?? I bought a 1932/33 ultra tiger console about a month ago the set was a complete wreck and is now sort of operational this one uses an AC/SGVM , AC/SG and AC/PEN along with a UU2 anyway the set will tune with good volume through half of the scale then volume on tuned stations on the other half drops to next to nothing with little to no background noise between stations either it does the same thing on both MW & LW everything seems to be withing spec all the Caps have been changed. And I'm at a bit of a loss with it. This is the earlier type of tiger three valves plus rectifier not the next year's four valve version. Attached Thumbnails

4th Apr 2020, 7:33 pm	#2
Mr 1936 Heptode Join Date: Mar 2017 Location: Romsey, Hampshire, UK. Posts: 524	Re: ULTRA TIGER TRF tuning bother possibly ?? I guess you may have checked already, but the two things I can think of are one of the tuning capacitor vanes shorting; or bandpass top coupling capacitor very low in value giving insufficient coupling at the LF end.

4th Apr 2020, 9:14 pm	#3
lloydwells Heptode Join Date: Aug 2016 Location: Dumfries, Scotland, UK. Posts: 550	Re: ULTRA TIGER TRF tuning bother possibly ?? Ok the tuning cap isn't shorting that was my first port of call on the rest of you post I'm gonna have to say nope didn't understand a bit of it please explain.

4th Apr 2020, 11:28 pm	#4
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: ULTRA TIGER TRF tuning bother possibly ?? Try cleaning the earthing contacts to the tuning condensor spindle. Is the weak end with the vanes closed or open?

5th Apr 2020, 10:34 am	#5
lloydwells Heptode Join Date: Aug 2016 Location: Dumfries, Scotland, UK. Posts: 550	Re: ULTRA TIGER TRF tuning bother possibly ?? With it closed its weak

5th Apr 2020, 12:19 pm	#6
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,764	Re: ULTRA TIGER TRF tuning bother possibly ?? Hi is there any corrosion where the vanes are fixed to the spindle ,also measure the capacitance when fully closed , Mick.

5th Apr 2020, 1:14 pm	#7
Mr 1936 Heptode Join Date: Mar 2017 Location: Romsey, Hampshire, UK. Posts: 524	Re: ULTRA TIGER TRF tuning bother possibly ?? Hi. The top coupling capacitor is the series one between the two tuned circuits in the RF front end. It will have quite a small value.

5th Apr 2020, 1:32 pm	#8
lloydwells Heptode Join Date: Aug 2016 Location: Dumfries, Scotland, UK. Posts: 550	Re: ULTRA TIGER TRF tuning bother possibly ?? Ok I have taken the tuning cap off stripped it cleaned it regreased the bearings and put it back together, this is a 3 gang condenser I've got 437, 440 and 445 pf whic isn't far from the 435pf on the diagram I'm going to give the chassis a quick tart up while it's off and I'll put it back on this afternoon.

5th Apr 2020, 8:52 pm	#9
lloydwells Heptode Join Date: Aug 2016 Location: Dumfries, Scotland, UK. Posts: 550	Re: ULTRA TIGER TRF tuning bother possibly ?? Well that's it all back together it's quite a bit better but still nowhere near perfect

6th Apr 2020, 12:37 pm	#10
D.Finney Pentode Join Date: Nov 2011 Location: Wigan, Greater Manchester, UK. Posts: 147	Re: ULTRA TIGER TRF tuning bother possibly ?? AS a matter of interest your set is identical to one I bought C.1976 from a dealer in Wigan, it worked well at the time; I gave it away about 20 years ago due to lack of space.