Re: old TV Tuners

[David Moisan <dmoisan@shore.net>]

>On 6 Nov 2001 at 10:36, Sven Franklyn Weil wrote:
>
> > > In the older TV tuners, each channel had its own tuned circuit.  It
> > > was possible, in at least some...
> >
> > Does this apply for modern-day manual-tuned sets?  I have a manual-tuned
> > set (with the knobs and the turrets for VHF & UHF) that was made in 1987. I

I've worked on many such sets, the last of which I only retired in 1994 (it 
almost caught fire).  Most if not all of them used a turret tuner for VHF 
and a continuously-tuning tuner for UHF.  You might remember tuning an old 
UHF set by twisting the dial (just right!) to get Ch. 38, and cursing 
whenever you overshot it.  The wide frequency range of UHF meant that a 
turreted tuner was very impractical.

Later (circa 1976 or so), the FCC required all UHF tuners to be _detented_, 
meaning they could be clicked through the channels like on VHF.  The same 
tuner was used but there was a click mechanism on the shaft so that UHF 
could be tuned as easily as VHF.  My first B&W TV was such a set.

Now, virtually all TV tuners are digitally tuned.  The only exceptions are 
the smaller black & white portables with slide-rule tuning and band 
switching like a shortwave radio.  (Usually, these have three bands for VHF 
2-6, 7-13 and UHF.)

I don't know when (or if!) the last turret tuner was made.  I'll bet 
they're probably still being made for some countries.

Take care,

Dave

David Moisan, N1KGH   ARES/SKYWARN                dmoisan@shore.net
Invisible Disability:  http://www1.shore.net/~dmoisan/invisible_disability.html
ATS-909 FAQ:  http://www1.shore.net/~dmoisan/faqs/sangean/ats909faq.html