06-12-2018, 04:15 AM
In respect of the difference between the Dynatron T99 and T99A modes, a little bit of triangulation comes up with the following.
Firstly, the T99 tuner as part of the Ether Conqueror V suite appears to have been announced in Wireless World (WW) 1951 October as a 1952 model.
That snippet is all I have. Unfortunately, the copy of WW 1951 October available at https://www.americanradiohistory.com/Wir...gazine.htm is devoid of most of the advertising pages. However, that Dynatron advertisement, if it can be found, might provide useful information for your RMorg entry.
Then in WW 1952 October is the following commentary in respect of Dynatron, in the Radio Show highlights article:
“The Ether Conqueror radio chassis (which can be purchased separately for £136 6s) has an overall gain which has proved excessive in some applications, and a pre-set IF gain control is now fitted as standard. This is not the usual bias control, but is a feedback arrangement which avoids disturbance of the response characteristic. Another new refinement is a bi-metal-controlled, temperature compensating capacitor in the oscillator circuit.”
This change may be correlated with the Dynatron advertisement in WW 1952 September, for the 1953 version of the Ether Conqueror V, in which the tuner was referred to as the T99A.
The T99B designation was mentioned in respect of the tuner portion of the Marconi Mimco broadcast receiver in a UKVRR thread. That model is thought to have had the Marconi model designation 1155A. It was announced in WW 1953 August. So the T99B might have been the 1954 model year version of the T99 for the Ether Conqueror V, with further changes, or it might have been a variant made just for the Marconi application, or perhaps it was the industrial version.
1951 October seems about right for the introduction of the T99 as successor to the previous T69 series that I think ended at T69D. One major change that Dynatron made was from Mazda 4-volt heater octal valves to Osram 6.3-volt heater miniature valves. Part of that complement was the X79 triode heptode, released around 1951 October. Basically it was the X78 rebottled in a noval envelope and base in place of the previous B7G, which had required that the cathode share on of the heater pinouts, an arrangement that I doubt was popular with the setmakers. Osram had opted for the B7G form rather than Rimlock for its initial range of miniature receiving valves, which included the X77 (same as the American 6BE6) heptode for the frequency changer function, but evidently British setmaker preference for the triode hexode/heptode forced it to offer such on a B7G base until the B9A base arrived. That the X79, which was not given a Pro-Electron designation, but did have American registration as the 6EA8 is probably attributable to AWV Australia, who manufactured and sold it under this designation.
Cheers,
Steve
Firstly, the T99 tuner as part of the Ether Conqueror V suite appears to have been announced in Wireless World (WW) 1951 October as a 1952 model.
That snippet is all I have. Unfortunately, the copy of WW 1951 October available at https://www.americanradiohistory.com/Wir...gazine.htm is devoid of most of the advertising pages. However, that Dynatron advertisement, if it can be found, might provide useful information for your RMorg entry.
Then in WW 1952 October is the following commentary in respect of Dynatron, in the Radio Show highlights article:
“The Ether Conqueror radio chassis (which can be purchased separately for £136 6s) has an overall gain which has proved excessive in some applications, and a pre-set IF gain control is now fitted as standard. This is not the usual bias control, but is a feedback arrangement which avoids disturbance of the response characteristic. Another new refinement is a bi-metal-controlled, temperature compensating capacitor in the oscillator circuit.”
This change may be correlated with the Dynatron advertisement in WW 1952 September, for the 1953 version of the Ether Conqueror V, in which the tuner was referred to as the T99A.
The T99B designation was mentioned in respect of the tuner portion of the Marconi Mimco broadcast receiver in a UKVRR thread. That model is thought to have had the Marconi model designation 1155A. It was announced in WW 1953 August. So the T99B might have been the 1954 model year version of the T99 for the Ether Conqueror V, with further changes, or it might have been a variant made just for the Marconi application, or perhaps it was the industrial version.
1951 October seems about right for the introduction of the T99 as successor to the previous T69 series that I think ended at T69D. One major change that Dynatron made was from Mazda 4-volt heater octal valves to Osram 6.3-volt heater miniature valves. Part of that complement was the X79 triode heptode, released around 1951 October. Basically it was the X78 rebottled in a noval envelope and base in place of the previous B7G, which had required that the cathode share on of the heater pinouts, an arrangement that I doubt was popular with the setmakers. Osram had opted for the B7G form rather than Rimlock for its initial range of miniature receiving valves, which included the X77 (same as the American 6BE6) heptode for the frequency changer function, but evidently British setmaker preference for the triode hexode/heptode forced it to offer such on a B7G base until the B9A base arrived. That the X79, which was not given a Pro-Electron designation, but did have American registration as the 6EA8 is probably attributable to AWV Australia, who manufactured and sold it under this designation.
Cheers,
Steve
