UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)

Notices

Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only.

Closed Thread
 
Thread Tools
Old 3rd Jul 2017, 10:12 pm   #21
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

The set does work on LW however it was working better before I replaced a couple of black hunts. Radio 4 seems ok, a couple of the French stations that were coming in very loud and clear are now very distant and can't tell what RTE is like as it is off air. Talk Sport has appeared around 2000 meter mark on LW. Talk Sport on MW appears at 275 meters (1089khz?).

Regards
Poppydog
poppydog is offline  
Old 4th Jul 2017, 8:17 am   #22
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ultra TR100 battery wires

Given that this set uses a PCB it would be very difficult to fit replacements for the black Hunts in the wrong position. What are their circuit designations and are the replacements of the correct value?

Personally I'd replace those red, yellow and black electrolytics. They're frequently faulty.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 4th Jul 2017, 8:19 am   #23
'LIVEWIRE?'
Rest in Peace
 
'LIVEWIRE?''s Avatar
 
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
Default Re: Ultra TR100 battery wires

I'm not sure if that should be called an Image frequency, but 149kHz is 2013 metres. Twice the IF is 2 x 470kHz or 940kHz. Add together 149kHz and 940kHz and you get 1089kHz. What i assume to be happening is that due to a combination of a very strong signal from the TalkSport Transmitter, which i believe to be quite a High power one, and poor selectivity in the TR100, the signal is 'rebroadcast' on 149kHz for reasons stated. Personally I wouldn't worry about this, as it shouldn't affect reception of any LW station, besides which it may be difdficult to prevent this from happening in any case.
'LIVEWIRE?' is offline  
Old 4th Jul 2017, 9:26 pm   #24
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

Firstly this is the only radio that I have that it is happening on.

With regards to there being a very strong signal from Talk Sport, its surprisingly not that great where I am in Cornwall, even though I am rather high. The red and yellow plesseys have caused me no end of trouble, so there has been a mass cull of them, I didn't actually get any music until I started replacing them (I'm assuming members that want to help have a sheet), C6 was the first replacement that enabled music. The hunts I replaced were as follows: C4, C2, C20, C14, these are all .04uf these were replaced with Vishay 47nf. C9 was a .1uf and was replaced with a 100nf. A couple of these were cracked, C4 I loosened the solder joints with repeated turning over and hooking back up so before I resoldered it I tested it and it was miles out of spec. The replacement transformed the radio. I haven't touched any of the IF transformer coils or the coils on the ferrite, the wiring from the ferrite looks good and the wave change switch is clean. The only thing I did try touching was TC3 and that managed to bring in the French stations a little closer. I think I had the trouble with Talk Sport after I had replaced C2 and C20.

Regards
Poppydog
poppydog is offline  
Old 5th Jul 2017, 9:45 am   #25
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ultra TR100 battery wires

Several of the capacitors you've replaced are in the front end of the set and changing them may have affected the set's alignment.

I hesitate to suggest it, but perhaps realignment is the way to go. Before you do that though do some voltage checks just in case a fault has been introduced.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 5th Jul 2017, 9:58 am   #26
GeoffK
Heptode
 
Join Date: Mar 2016
Location: Essex, UK.
Posts: 602
Default Re: Ultra TR100 battery wires

Any realignment should be only to the oscillator coil, not the IF's even then it should really be left alone, the risk of breaking a core is not worth it. The only program that you are likely to listen to on LW is Radio4 (until their ancient transmitter valves give up and they close LW) so if that works then why bother to fix the Talk Sport ghost station with the risk of ruining the radio in the process. Voltage checks, and component layout, should be carried out as suggested.
__________________
Geoff
GeoffK is offline  
Old 5th Jul 2017, 10:24 am   #27
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ultra TR100 battery wires

The image frequency of a station differs from the station's actual frequency by twice the IF. The IF in this set is 471kHz. In the case of Talk Sport 1089-(2*471)=147kHz, which is about 2040 metres which is where the OP reports hearing the ghost station.

To put it another way, If the set is tuned to 147kHz the Local Oscillator frequency will be on 147+471=618kHz. 1089-618=471kHz, which is of course the IF.

Image reception is down to poor selectivity in the front end, so I'd say it's the RF section which MAY need adjusting.

There are no cores involved here. Has the OP perhaps accidently moved the coils on the ferrite rod?
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 5th Jul 2017, 11:34 am   #28
GeoffK
Heptode
 
Join Date: Mar 2016
Location: Essex, UK.
Posts: 602
Default Re: Ultra TR100 battery wires

A Philips MW/LW portable also picks up Talk Sport on around 150kHz fairly loud. And a Roberts Rambler picks it up in the same place only much quieter. So it seems to be an image rejection issue. The Ultra TR100 will be having the same issue with image rejection. It could be that the Talk Sport transmissions have some sort of fault causing it to transmit a signal on LW though is more likely caused by the interaction of the IF frequency.
__________________
Geoff

Last edited by GeoffK; 5th Jul 2017 at 11:39 am.
GeoffK is offline  
Old 5th Jul 2017, 11:38 am   #29
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ultra TR100 battery wires

Quote:
Originally Posted by GeoffK View Post
It could be that the Talk Sport transmissions have some sort of fault causing it to transmit a signal on LW.
Anyone able to check using a double or triple conversion receiver?

1089kHz is a strong signal here in Ipswich, but listening on LW on a triple conversion receiver shows nothing untoward around 147kHz. Just an Algerian? station on 153kHz.

Maybe it's different in Cornwall?

EDIT. Just tried listening on a few domestic sets with IFs around 470kHz. No Talk Sport image on LW.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 5th Jul 2017, 12:02 pm   #30
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
Default Re: Ultra TR100 battery wires

Quote:
Originally Posted by Station X View Post
Quote:
Originally Posted by GeoffK View Post
It could be that the Talk Sport transmissions have some sort of fault causing it to transmit a signal on LW.
Anyone able to check using a double or triple conversion receiver?


A TRF may be easier to find for longwave.... no images there.
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Old 5th Jul 2017, 1:22 pm   #31
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

Thanks for the replies. The voltages on the transistors and the current being drawn were nothing like they should have been hence the cap changing exercise, however I haven't checked their voltages since the cap replacements. That's the first thing I will do tonight. Regards Poppydog
poppydog is offline  
Old 5th Jul 2017, 1:23 pm   #32
GeoffK
Heptode
 
Join Date: Mar 2016
Location: Essex, UK.
Posts: 602
Default Re: Ultra TR100 battery wires

A small Pye MW/LW set also picks up a very faint Absolute Radio (on 1215kHz) signal at the very low end of its LW travel so not confined to Talk Sport near it. It should be pointed out that none of the radios mentioned have been opened, apart from putting cells in.
__________________
Geoff
GeoffK is offline  
Old 7th Jul 2017, 9:01 pm   #33
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

Apologies for the delay in replying as I had current issues again but I think this is now sorted (bias resistors). I will say again, this is the only radio I have that is doing this, none of the others I have have Talk Sport on LW. With regards to realignment I have no gear for that, also those transformer coils have not been touched as they still have the goo they were sealed with from new, so would almost certainly take some moving. The coils on the ferrite are untouched from new I reckon. The voltages on the transistors seem ok to me I can post them on here if members want to look at them, someone may see a discrepancy that I don't. I don't know if there is anywhere else anybody suggests I look as its a bit strange I replaced the hunts caps almost like for like and end up maybe realigning, I almost feel like putting the old hunts back in .

One more question: the capacitor across the speaker terminals is not good, does it really need to be there, what's its function?

Regards
Poppydog
poppydog is offline  
Old 7th Jul 2017, 9:14 pm   #34
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Ultra TR100 battery wires

I'm out of ideas. Perhaps the best thing to do is leave it alone as suggested in post #26.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now  
Old 8th Jul 2017, 12:19 am   #35
AC/HL
Dekatron
 
AC/HL's Avatar
 
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
Default Re: Ultra TR100 battery wires

It seems to have changed at post 21, was it working better before that?
AC/HL is offline  
Old 8th Jul 2017, 2:25 pm   #36
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

Thanks for all the replies. I am going to leave this as it is, its a bit of a cop-out but I've managed to get a non working radio with an enormous amount of faults working and sounding very well (apart from the talksport issue).
poppydog is offline  
Old 8th Jul 2017, 3:22 pm   #37
AC/HL
Dekatron
 
AC/HL's Avatar
 
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
Default Re: Ultra TR100 battery wires

Interesting radio as it was Ultra's first transistor model, 60 years old next year, along with just a few others following on from Pye's toe in the water revolution.
AC/HL is offline  
Old 10th Aug 2017, 10:26 pm   #38
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

I will try asking this question again. Is it OK for me to remove the capacitor across the speaker as it's using the single 9V battery instead of the two 4.5V with the centre tap going to the speaker?

Regards, Poppydog.
Attached Thumbnails
Click image for larger version

Name:	20170810_183936.jpg
Views:	75
Size:	94.4 KB
ID:	147659  
poppydog is offline  
Old 10th Aug 2017, 10:42 pm   #39
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Re: Ultra TR100 battery wires

The capacitor across the speaker is to provide top cut, a sort of tone control may have something to do with the speaker's frequency response.

It's a Non polorsied electrolytic may well be faulty but won't make much difference to the radio's sensitivity. Removing it will probably make the set sound "bright" rather than the fashion of the time, mellow.

Cheers, Mike T.
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 19th Aug 2017, 8:44 pm   #40
poppydog
Banned
 
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
Default Re: Ultra TR100 battery wires

Thanks for your reply Mike, sorry for the delay in replying.

The ultra needs that cap across the speaker. Lifted one end and my tester says its OK (the only one that was), however the radio is not if it's disconnected. At low volume it's really distorted, mid to high volume it's fine, however there is no change in the tone at all. If I push it back into contact with speaker tag, the distortion clears. There is also a squeak when turned off with it disconnected, so it's staying. It seems the cap does a little more than just tone control.

Regards
poppydog
poppydog is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 6:40 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.