National Panacolour Delta Gun TV
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Location: Mildura, VIC
Member since 5 May 2011
Member #: 896
Postcount: 108
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Hi all, Been a long time since I last posted here, I have recently acquired a Genuine Delta Gun National Panasonic Vintage TV, it is the first of the remote control types ever released here, This uses the Ultrasonic type of remote control, before the infrared ones!! The Turret tuner is driven by an AC Shaded pole motor!! which pulls its rotor into gear, Similar to Car Starter motors, very cool!!
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Location: Ballarat, VIC
Member since 4 January 2011
Member #: 803
Postcount: 456
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Nice find, the first generation colour TV's are getting hard to find these days.
The National is possibly the only colour set sold in Australia with a mechanical remote controlled tuner, I can't think of any others at the moment.
It was a strange choice as they had a suitable electronic tuner they could of used with the remote system but they stuck with the rotary tuner and motor.
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Administrator
Location: Naremburn, NSW
Member since 15 November 2005
Member #: 1
Postcount: 7290
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The motor must have been geared right down - shaded pole motors are quite gutless by all accounts and usually see service running domestic exhaust fans. They can build up quite a few revs but have very low starting torque.
Was this telly VHF-only or did the UHF rotor allow remote control as well?
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A valve a day keeps the transistor away...
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Location: Ballarat, VIC
Member since 4 January 2011
Member #: 803
Postcount: 456
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I think they were all VHF only.
The shaded pole motors had a large gear reduction. Most of the TV brands in the 1960's had a corded remote TV model available for those who could afford the option. Nearly all of them used shaded pole motors and gearbox.
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Location: Belrose, NSW
Member since 31 December 2015
Member #: 1844
Postcount: 2363
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Hi Larry
I know that TV well. I used to work on them when they were new, under warranty.
Some issues I recall:
The 90 degree deltagun CRT is a US-made RCA tube. It suffered from flashovers which would take out the RGB output transistors but more often the colour difference amp transistors and clamp diodes. You can improve the situation by removing all the aquadag grounding straps from around the CRT, everywhere except the one going back to the CRT socket.
The red on that CRT is not really red but more orange! The phosphor is very non-linear, there is an R-Y gain control but it is hard to get good fleshtones without also getting overpowering luminous reds. It was usually better to set the colour temperature "hotter", i.e. more towards the blue, to counter this effect.
I wonder how good the CRT is. As I recall they didn't last as long as other tubes. It is possible to use a tube from an old Decca hybrid, there were many of these discarded in the early days of colour still with good CRTs.
Regards the rotary tuner - in the early to mid 70s you needed to be able to tune band II channels (4, 5, 5A) and most varicap diode tuners then available did not do this. There was also some concern about selectivity, sensitivity and adjacent channel rejection in a crowded VHF band. So no Australian maker risked releasing a set with an electronic tuner. Plus, it costs money to tool up for a small-volume model that would need a different front. Much easier just to drop in a gear drive assembly...
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