Hi,
Digging around in the workshop there was a box marked up ex Telequipment Monoscope parts and in amongst was this Haynes Radio Ltd T33 transformer. I think this is designed for line scan operation since possibly EDA refers to Efficiency Diode Anode, H.HT might suggest High HT or boost voltage and the Anode connection is via a high voltage porcelain insulator. The case is sealed.
Winding dc resistance is 43 ohms between Anode and H.HT connections, with 3.5 ohms between pins 2 ~ 3, and 1.8 ohms between 3 ~ EDA.
Guessing from the information for each of the connections I think it may operate with an efficiency (boost) diode as:
Research on the Haynes company says they pulled out of TV manufacturing around 1951, but maintained a big business in wound components for home constructors. Does anyone have information, ideas or data on this transformer, or indeed the Telequipment Monoscope (Test Card C Generator)?
Cheers
Rich
Haynes made the wound components specified for several magnetic scan TV sets in the ate 1940s - early 50s. I thought that the the 1948 Wireless World unit was an example but looking at my 1948 bound copy, there were no Haynes components. I have seen at least two examples but, at the moment, can't find them. I know that their products were on sale to the amateur constructor, LOPTs. FOPTs , BO xfmrs and scan coils.
A bit belatedly, I have found references to Haynes home constructed TV components in "A Modern Home Built Televisor" published by Electronic Engineering 1948 (2nd Edn.).
LOPT ------- TW6/126
scan coils -- S912
Focus coil -- F912H
EHT Xfmr --- (4kV) TJ.18/4000.
The EHT transformer has a 230V primary. The design uses EF50s and Mazda valves and looks like a very interesting set to build and can use the normal 9" CRTs of the time e.g. MW22/7, CRM92 or 6051.
I could supply scans of the booklet if anyone has a serious interest - I say "serious" as there are 80 pages!
Hi, Thanks for information on their home constructed TV components as data on them seems to be hard to find. Clearly many of these parts were manufactured prior to 1951 when Haynes pulled out of TV manufacturing. Certainly I would be interested in the Televisor construction article but at the moment such a project would never get started until a suitable tube was available. Interest level is at very curious rather than serious.
With regard to Haynes T33 transformer, it appeared in the Telequipment Test Card C generator manufactured round about 1961. In the box of parts there are several Brimar 6BG6G and 6CD6G line output valves so suspect one of these together with a 6U4 might have been used. For this application, scan linearity would have been paramount so likely to have not been driven hard.
The Telequipment monoscope tube was manufactured by GEC and quite a while back by coincidence one appeared on a famous internet auction site.
I wonder if Marconi used the same tube in the BD665 monoscope?
Also in amongst the parts box there is a mains EHT transformer built in a similar fashion to the Haynes LOPT. It has a 2 volt winding for a HVR2 or similar. Unfortunately the metal casing had been wrenched off and several porcelain insulators smashed (looks like its been belted with a hammer!). I have never powered it up but estimate maybe 3 kV output as the three 0.1uF EHT filter capacitors are rated at 5kV each. This stuff has been tucked away for 30 odd years but still remember many of the senior engineers insisting the EHT transformer be destroyed and junked since it was in no uncertain terms lethal.
Cheers
Rich
