Baird T6 and T7 at Radiolympia 1936
I just came across descriptions of these sets from someone visiting the show.
It's interesting that the T6 is of similar form to the T5 (i.e. mirror lid) but with a 12" CRT and a radio but is cheaper than the T5.
You may need to zoom out your browser to see the two page presentations.
Television Receiving Sets. Several television receivers were displayed at the radio show at Olympia. In some cases the manufacturers have not announced prices and in others no information.of any kind is available. Baird television receivers are manufactured under license by Bush Radio, Ltd., in three models, the T-5, T-6, and T-7. Prices have not yet been announced, but it is understood that type T. 5 will sell for about £90 – 10 shillings and T.6 about £78 – 10shilling, A special type of aerial is required for this receiver. - Electrical and Musical Industries, Ltd. ("His Master's Voice") have produced two, 900 and 901, General Electric Co., Ltd., also shows two, BT 3701 and BT 3702, and Pye Radio Ltd. two with models 4200 and 420l. E. K. Cole "EKCO – Scophony, likewise shows two, 201 and 202. Available information regarding these models follows: TYPE T. 5
TYPE T. 6 The general design and construction is similar to the large model T.5 already described. The T.6, however, in addition to receiving the transmissions of both vision and sound on the ultra-short waves, also possesses the added advantage of being able to receive pro grammes ln the Medium and Long Broadcast wavebands. The value of this will immediately be apparent, for not only can full pleasure be de rived from the daily television transmissions, but by operating a single control the set is converted to a broadcast receiver, capable of good quality reception from a number of British and foreign broadcast programmes. - - - - SIZE OF PICTURE. The size of the Picture shown by the T.6 is lo ins. by 74 ins., only slightly smaller than the T. 5, and is seen on an inclined mirror as in model T. 5. "CATHOVISOR" CATHODE RAY TUBE. This is mounted vertically below a safety glass window. In Picture brightness and life, this tube has the same outstanding features as the one in corporated in the T. 5 model. WALWES, POWER CONSUMPTION. A total number of 14 valves (including two mains rectifiers) are included in the five chassis, while the power consumption is lé0 watts. CONTROLS. The controls on this model are arranged somewhat differently from the T. 5. The two main ones, focus and brightness, are on the sloping panel at the top. Below this is the broadcast tuning, complete with dial, change-over switch for either television sound or broadcast sound on medium and long waves, sound volume control, together with two preset controls, which are adjusted on installation. the sloping fret at the base of the cabinet. CABINET. As illustrated below, this is in Walnut. Dimensions: height (closed) 4l in. , height (open) 50 in., width 2l in., depth 17 in.
I have a brochure covering these sets. No illustration of the T7, but a good illustration of the T6.
It is probably the most expensive piece of paper I have ever bought...
In due course, yes. It's a funny-looking thing and the radio dial is unlike any contemporary Bush set.
Here you go, Peter.
That's excellent Mike! Do you happen to know if the T6 was exhibited at Radiolympia in 1936 or would Andrew W. Cruse who was reporting on the show above just have seen your brochure? Do you know if any T6s still exist?
The position of the pre-set controls door indicates that the T6 has different timebase and perhaps receiver assemblies.
The T5 has a TRF sound receiver, independent from the superhet vision receiver. It might be that the sound receiver in the T6 is a combined radio and television sound assembly.
According to Andrew W. Cruse it only has 14 valves. That sounds quite modest for a set incorporating a medium and long radio.
"VALVES, POWER CONSUMPTION. A total number of 14 valves (including two mains rectifiers) are included in the five chassis, while the power consumption is l60 watts.
CONTROLS. The controls on this model are arranged somewhat differently from the T. 5. The two main ones, focus and brightness, are on the sloping panel at the top. Below this is the broadcast tuning, complete with dial, change-over switch for either television sound or broadcast sound on medium and long waves, sound volume control, together with two preset controls, which are adjusted on installation."
Perhaps he didn't look in the little double doors.
I believe Till is right - the sound receiver is a TRF for both radio and TV.
Reading what you quoted in the original post Peter, it does read remarkably like the text of the catalogue. Another time I'll post the description page from the catalogue for the T6.
Just checked the description in the catalogue with the text - it's a copy.
It has to be said that Baird (Bush) were very good at getting a quart out of a pint pot where valve counts were concerned.
Thanks Mike. The HMV901 has 21 valves with four being a superhet sound receiver that could have also functioned as medium and long. The 901 is perhaps a bit extravagant having three valves for sync separation but it doesn't have a video amp. The T6 description talks of two mains rectifiers but I guess that could be one HT and one EHT. That would reduce the 901 count to 18. To get down to 14 that would leave only 4 valves in the TRF vision receiver although two RF valves in the 901 sound receiver make no contribution to vision gain so they could be reassigned but we are still two valves short!
"T.6 about £78 – 10shilling, A special type of aerial is required for this receiver."
Perhaps a higher gain aerial was the solution.
"Special type of aerial" = not your normal long wire!
If the vision receiver is like those in later models, it's three TSE4s and a D1 (?). Big problem is that secondary emission valves tend to be both noisy and very critical of bias on the secondary cathode.
The other thing I've seen on Baird sets is reflexing - the T21 does this with the 1st AF amp, pressing it into service as a sound RF amp (an SP4).