Reception problem

[arcadus]

I have a combination antenna (with booster) mounted just under a E-Genius cordless phone antenna. Occasionally, the TV's signal quality will drop to zero but signal strength remains around 80%. To fix this, the antenna is unplugged from the TV for a few seconds. When reinserted, signal quality is restored.
Why is this so?

[mtv]

Without accurate signal measurements, it's difficult to determine, however, it's likely your signals are on the 'digital cliff edge' and sometimes go below (or above) the operating window.

Temporarily removing signal from the TV tuner then re-applying it may give the tuner an opportunity to re-lock onto the signals.

It's also possible your amp is set too high and causing an overload.

Noise is another possible issue, either from signals, the amp itself, or a combination of things.

With digital, you need sufficient signal quality at the antenna to maintain reliable reception.

Amplifying a poor-quality signal will only make it a 'louder' poor signal, so the signal strength reading you have is likely false.

Where are you located? Where are your TV signals being received from (eg: which transmission site)? What make & model of TV antenna? What make & model of amp? Is your coax well-shielded? (eg:RG6 Quadshield).

How is your antenna mounted..... eg: ridge of roof on guyed mast, etc etc...... the more info the better.

[arcadus]

It is located about 100k from Adelaide transmission site. (Vast calls it a grey area). Reception is not good. Some nights most channels are OK with one, nine and ten being the most troublesome. On occasion, reception can drop to only SBS.
The antenna is a"fringe" zone antenna mounted on a 1.5M pole just above the gutter.The coax is being reused from an Austar installation- not sure about the amp except that it is a Hills.

[mtv]

With digital, height isn't everything, but at around 100klm from the TX being only mounted 1.5m above the gutter won't be helping.

Antenna mounting location can be critical in marginal signal areas. Even just a few centimetres in any direction, including up or down, can make a huge difference.

High-gain single band antennas will outperform a single combination antenna in marginal signal areas, so I suspect your antenna and its mounting position are less than ideal.

As I mentioned, the key to reliable digital reception is ensuring there is sufficient signal quality 'at the antenna'.

Only then is an amp useful.

Austar cabling is either trishield or quadshield.... both of which would be fine.

You didn't mention what town you are in, so I can't check if there are any other translators which may service your area.

[arcadus]

Located at Purnong SA. As you suggested, the TV is relocking after losing the signal when the plug is reinserted?.
I was looking at relocating and perhaps replacing the antenna. Just about all antennas here have boosters especially in the river valley.

[mtv]

Distance from Purnong to the Mt Lofty TX is around 85klm.

From experience, I'd be using a Hills DY10 or DY14 band 3 antenna on a tall mast.

You may not even need an amp.... just depends on signals arriving at the antenna, how many outlets, etc.

The majority of amps are left over from the analogue days and a lot of older amps have a high level of self noise, which is detrimental to digital.

Another possibility is the new digital translators at Mannum, which is around 25klm from you at the Broadcast Site, Quarry Reserve adjacent to East Front Rd.

These are all band 5 UHF horizontally polarised on RF channels 41-45.

They are much lower power than the main Adelaide transmitters and they are intended for the Mannum area, which had poor reception from Adelaide, so I think the Adelaide signals are still your best bet, with the right antenna and mounting.

Once again, it's almost impossible to know exactly what your signals are doing without being there with test equipment.

[arcadus]

The Mannum translators appear only to work for Mannum and towards the west.
I will look into purchasing an antenna you have suggested.
Thanks for your help, much appreciated.

[mtv]

Unless you have some nearby obstructions, your signal path to Mt Lofty is clear.

Raising the antenna height significantly should make a big improvement.

As SBS is now on VHF from Mt Lofty, you'd only need a UHF antenna for the community channel (CTS on Ch 33) which may also eventually move to VHF Ch 10).

A good low-noise amp I regularly install is the Kingray MDA20H

It's fully-shielded but the pic in the link shows it with the cover off.

Let's know how you get on.