Hi all,

Does anyone out there know of a digital HD set-top box that can be used with both UHF and VHF televisions? I have an Altech UEC DT3900RF RF output set top box, but the television needs a UHF tuner to recieve signals from it

This can be troublesome as I have a couple of vintage VHF televisions which don't have UHF receiving capabilities.

Thanks,

Chris

I'm sure you though of this, but a separate VHF TV modulator fed by the baseband video and audio from the set top box may work, though it's more stuff to have atop the TV set (or dangling behind it). Though if the TV set you want to watch is a B&W, use the luma output of the set top box (no chroma subcarrier), if you can set the Y Pr Pb scan rate to standard definition (625i/50). I have a very old American B&W TV set made before colour TV was developed, and it will present the entire bandwidth of the luma on its CRT, including the chroma subcarrier if I don't use luma. Are your older B&W TV sets like this, made before colour was deployed in Australia?

If your set top box has composite video/audio outputs via RCA sockets then you can get a VHF modulator from Jaycar to convert to Ch 0 or 1 on any telly with a VHF analogue tuner.

Wa2ise, I think I only understood half of that technical talk... Then again, it's only 9:00 and I haven't had any coffee yet!

The two televisions in question are a late 60's/1970s 12" AWA valve portable (I've started a thread about this in tech talk) and a 1980s 10" Philips Natural 10 model KA910 portable.

Brad, thanks! I'll have a look when I go back. I need a few bits and pieces. Are these VHF modulators expensive things?

Chris

Should be less than $50.00.

Don't know how it was in Australia, but back in the 50's and early 60's, most TV sets in the USA only came with VHF tuners. UHF was an option, and if your city had VHF channels people usually didn't pay extra for this option. Which meant that anyone trying to establish a new TV channel on UHF would be pretty much doomed to fail (go out of business) as few viewers were equipped to tune your station in. Our FCC in around 1964 mandated that TV sets sold after then were required to have UHF tuners as standard equipment. It turns out colour TV here didn't sell much until after this date, so most VHF only TVs were B&W. Which lead me to guess that your vintage TVs without UHF were B&Ws. Are your vintage TVs colour or B&W?

One is a black and white (and a valve set) AWA P1, the other is a colour solid state Philips KA910.

UHF came in here just after colour. The first coloured sets were sold in 1974 and all major networks and many rural stations were transmitting in colour in 1975 as far as I know.

There were a few early coloured sets that only had a VHF tuner but sets with a second dial for UHF tuning quickly became popular, along of course with sets featuring push button tuning and ultrasonic remote control.

Betamax and VHS video tape recorders came out about the same time though all these had both VHF and UHF tuning.

Before aggregation of rural television stations each non-metro viewing area only had two channels. The Government-owned ABC and a local commercial station, most of which were bank manager's nightmares because they were always broke. When the Commonwealth finally decided that rural areas should have three commercial channels each station was then permitted to broadcast in neighbouring areas so there was always an overlap and greater choice. Until this point in time UHF was only used for repeaters. Main transmitters for each station remained on VHF. Between aggregation and the arrival of digital television, UHF was used almost exclusively with the government promising better pictures and all that jazz though in reality, UHF was the obvious choice because there were far more channels available. In Australia, Channels 0-12 (including the odd-ball Ch 5A and Ch 9A) occupies the VHF band and Channels 21-69 occupies the UHF band. Not all of the channels in each band are used though. Channels 3,4 and 5 fall into the internationally recognised FM radio band. Channels 21-27 seem to be stuck in a timewarp for some reason that only the Department of Communications knows about.

I have an old VCR with AV inputs I use to connect my settop box to the old telly in the shed.
Beauty is you can get an old vcr for next to nothing
The other bonus is you can play some old school telly shows with it

I've got a not too old 13.5" TEAC telly & dvd player combo unit I found on the street. Works perfect, so now I have it up in the garage so I can watch it from my work bench.

Chris

Back in the olden days of TV, before the above mentioned FCC UHF mandate, Americans could buy and use UHF to VHF converters. These would be essentially be like the front end of a radio receiver, tuning the UHF band like a radio, and the IF would be on our channel 6 (82-88MHz). Maybe you can find one of these, or an Aussie equivalent, to get your UHF set top box output on a VHF channel.

There's a UHF to VHF converter on the right of the digital TV converter boxes atop this TV set.


Another UHF to VHF converter, this one calibrated in frequencies instead of channel numbers.

Nice-looking box there. I cannot ever remember seeing a device like that here though. As suggested by another member one could use a VCR in place of the modulator I suggested but then again, an older VCR which outputs to Ch 0 or 1 would serve the same purpose as this box.

Some VCRs in Australia alternatively outputted to Ch 3 or 4 instead though these disappeared from the market in favour of 0 or 1 due to 3 and 4 being located in the FM radio band. VCRs made in the last 15 years outputted to Ch 36 which is no good for what is needed here.