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-   -   Ultra portable 1400 (https://www.vintage-radio.net/forum/showthread.php?t=156383)

bionicmerlin 7th May 2019 8:56 pm

Ultra portable 1400
 
3 Attachment(s)
I have just got this lovely set up and running.its been in dry storage all itís life .prior to switch on I replaced the mains filter cap and a capacitor that was leaking and cracked. A couple others was running hot after 10 mins so these were replaced . Picture is pretty good but there is a slight compromise between both standards with me setting 625 lines for the best results.
There is curve on the side of the screen and thatís with the correction magnets bent fully in. I might try a stronger magnet to see if that helps.
Is there any more recommendations or mods that should be carried out for reliability or is it best left as it is. This set has the letter C on the board so is this a later version. Sorry the pictures are not that good Andy

jayceebee 7th May 2019 10:46 pm

Re: Ultra portable 1400
 
Hi Andy, that's looking very good. There are a number of modifications that can be done to improve reliability and performance especially on 625. Have a look at this thread and particularly post 34 by Heatercathodeshort.

John.

bionicmerlin 8th May 2019 2:31 pm

Re: Ultra portable 1400
 
John hi .
Thanks I donít know how I Over looked that other thred I the first place Andy

Heatercathodeshort 8th May 2019 7:09 pm

Re: Ultra portable 1400
 
The two 'S' curve capacitors C108 .3uf 405 and C107 .1uf 625 are often overlooked when faced with odd line linearity on the 900/950 and 1400 series Thorn chassis. Worth a check. They go S/C, easily measured on any cheap meter. John.

jayceebee 8th May 2019 8:33 pm

Re: Ultra portable 1400
 
R70 39k going just a little high in value can also cause line scan crushing at the centre of the raster which varies with brightness.

John.

GLENZ32 9th May 2019 1:28 am

Re: Ultra portable 1400
 
Nice looking set and a great picture considering the minimal work done so far :)

bionicmerlin 9th May 2019 1:30 am

Re: Ultra portable 1400
 
Thank you both For the things to check
I did change C 107 .1 MF as it was getting hot. I will check the other cap and the R70 resistor I will check also. I donít know how you guys remember all this stuff . Thanks again Andy

Heatercathodeshort 9th May 2019 9:19 am

Re: Ultra portable 1400
 
Just a side thought Andy. Old boys like myself learned the trade from hard copy, books, trade journals, manufacturers service data, service manuals and update sheets.
These were read and studied, result, experience gained.

I think the problem today can be attributed to the 'look it up on the Internet then forget it' culture that is all part of modern life. Without doubt it does nothing to train a memory!
Regards, John.

bionicmerlin 10th May 2019 8:00 pm

Re: Ultra portable 1400
 
John . I did change R70 it was about 47K I didn’t think that too bad to start but thinking about it that must be about 20% over the odds. I didn’t notice too much difference apart from slight increase in width. I been playing about with a extra magnet to take out the curvature on the left of the picture. I have had good results but the horizontals on the test card slightly curve at the edge. I think though that’s about the best I’m going to get it.

I do have a slight increase in height switching between 625 and 405.

John (H/C) well I’m glad people like yourself help me on the internet. I might open a new thread as I’m not sure everyone had so much knowledge.

Andy.

Focus Diode 16th May 2019 5:45 am

Re: Ultra portable 1400
 
Excellent result. I have an older Ferguson 3645 model which initially led me a merry dance.

https://www.vintage-radio.net/forum/...d.php?t=149566

Hybrid tellies 16th May 2019 9:41 am

Re: Ultra portable 1400
 
After the bitter experience of losing a really good 1400 16" transportable set, the best 1400 I had ever seen, to a fire. I strongly I strongly recommend that you check the width control is 2.2M and R145 is 680k.
If this mod has not been done please do it before you do anything else.

bionicmerlin 17th May 2019 10:39 am

Re: Ultra portable 1400
 
Thanks for the link FD .i missed that before. I got a few couple more larger 14oos to do so I might have to revert back to these this link for more tips.
I do have a slight hight difference between 625 and 405 not much to worry about but I will do a couple more checks .
Simon HT
Yes mine has not had that mod done. I was checking last night .i do have some new old stock 2.2 M pots that are exactly the same as the original. On testing they all read about 1.8 M having clearly got 2.2 stamps on them. I guess they might work . I will give them a try Andy


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