Thread: TV antenna masthead amplifier choice - 24dB or 32dB?

dbs in fringe areas are like horse power - you can never get enough

Before choosing these amplifiers did you consider what stations/tower(s) you are interested in.

Are the station(s) you are after UHF or VHF or both ?, this will determine your antenna(s) and amplifier type.

If you are after both VHF and UHF from one tower a combo type antenna and either of the two amplifiers you mentioned will do.
If you're after EITHER VHF or UHF from either of two towers then you'll need two aerials (one VHF and one UHF) and again either of the two amplifiers will do.
On the principle of more is good, I'd go for the higher gain (32 d , cant use decibell letters as it gets turned into emoticon ) version.

Any other combination it starts to get a bit more complicated and these amps won't do.

Note that the two amplifiers you have selected have F type connectors which is a good thing if you have the right tools / skills but no good to you if you don't.

Deano

I had master antenna come out and install an antenna on the roof for me about 2 weeks ago. I'm on a fringe area and my reception went from nothing to booming with the lowest gain. I asked the person if it was worth getting the higher gain just to make sure and their comment was to get the right gain - to much is as bad as too little. Anyway, the entire install was $230 total from somebody with all of the right knowledge and equipent to do the job properly.

Before going active gain via amp, you should get what ever signal quality you can by using the highest gain antenna that you can. Directional gain is good as it excludes unwanted signals. Active amplifiers boost everything that is put down their throat. If you have strong signals getting to your amp you could end up with intermodualtion products which will generate unwanted signals in band.

When using two antennas you need to have an appropriate combiner or you have to use an RF switch to select one antenna at a time. You cannot just solder the feed of two antennas together as it will upset the impedance match.

How have you combined your two antenna signals?

OK Scouse,

First question - which two antennas (VHF and UHF) do you actually have?

Next Question - are they connected to the down feed via a properly matched diplexer/triplexer/filter to separate the VHF and UHF signals and stop crosstalk issues if you do go for active amplification sooner or later?

Next Question - are you using good quality "F" connectors that are compression fitted (or at least properly crimp fitted)?

Next question - do you plan on re-cabling any/all of the existing ports eventually (this will affect how you set up the cabling - multidrop or network)?

Remembering that unlike the old analogue system you can't just vaguely point the antenna in the direction of the tower, you need to be within 1deg of arc either side of it to have much chance of getting a decent, error free signal.

Do you have any signal strength metering equipment (or any signal quality measuring equipment for that matter which is even more important)?

If you had the eyes of an eagle, could you see the top of the transmission tower or is there a hill (or even a clump of trees) in the way of your line of sight? If so, you need to get the antenna(s) higher as the first step. Perhaps you need to move the antennas to a different part of the roof where you have a better line of sight to the tower.

I lived in the Southern Highlands for many years and could get Sydney and Wollongong stations just fine. Two high gain antennae. VHF for Sydney, UHF for Wollongong. Pointing in almost opposite directions and nicely filtered and diplexed.

I ran two points happily but needed a small boost in signal for the Sydney stations when I went to five outlets. Even without the amp I managed about 60dB from Sydney (at almost 125km point to point) and closer to 76dB for the Wollongong tower on Knights Hill (very much closer but UHF so trickier).

I was lucky that the earth had a bit of a dip between me and Artarmon. Not so lucky that there was a forest in just the wrong spot for the line to Knights Hill. This resulted in the VHF and UHF antennas being in different places on the roof. Sometimes just stepping sideways a metre can make a huge difference (particularly if it's the wrong way and off the roof )

Now, I have all the test gear, and all the hardware to do this. I have many years of communications training courtesy of time in the Signals Corps and being a radio amateur for a number of years. Plus I did antenna installs part time for a while when people were just catching on to this DTB stuff.

So in short, if you've got the gear to run, cut and terminate your coax. If you have the right signal metering and analysis equipment and the time to get it sorted. If you have all the hardware to hand should you need it like splitters, amplifiers, diplexers, filters and such. Then if so, go for it.

If not, do as Simon suggests and get a professional (or at least a mildly trained person like a Mr Antenna franchisee) to do the work for you. It'll be better and quicker in the long run.

Anyway them's my thoughts on it all.

If you decide to go for it yourself, and more power to you if you do, feel free to let me know if you have specific concerns or just need to talk it through with someone.

Cheers,
Iain

Scouse will be using the right fittings and tools. I've lent him my cable shears, strippers, flaring tool, crimping tool, etc.

I wouldn't bother with a VHF antenna. I did away with mine and installed two UHF antennae, one aimed at Sydney, the other aimed at Knight's Hill (Kiama). The antenna aimed at Kiama is the higher gain of the two. These are fed into a combiner (in a cupboard below the cable entry point) then the single output of that goes into an amplified splitter (Kingray SA164F). That gives me four outputs to feed different rooms.

Sounds to me like you're off to a pretty good start Scouse.

Thanks to Ron and his gear the labor intensive stuff is well and truly covered.

I am assuming you've also talked to Ron about this install, and I suspect he's got you to a reasonable starting point.

Thanks to you Ron for loaning the necessary tools.

I ran the VHF yagi pointing to the Sydney towers because the Sydney UHF repeaters were all rubbish signal from my part of the world then. I could pick up a Canberra signal better than Sydney on UHF. Good to hear your dual UHF arrangement is working where you are Ron.

Good luck with it all Scouse. You know where to find us.

Cheers,
Iain

Originally Posted by RangieBit

I am assuming you've also talked to Ron about this install, and I suspect he's got you to a reasonable starting point.

He has & I'm going back to basics by replacing the dodgy cabling & doing without an amplifier to see how that works out before I do anything else.

Thanks all for you advice. I must admit that most of it went over my head though .