How Much Power?

[68OD636]

How much power can realistically be put into a DV27 on a ground plane in the loft?
How does a linear work?
If you had say a 500w linear, would your output be a genuine 500w?

Sorry for the basic questions, never used a linear before!!

[ryan_paul]

A Linear has a input and output power for example 1 watt in gives 2 watts out or 3 Db gain.

the two things I would say about liners is that you will dammage your liner if you "over drive" it. This means you have exeeded the maximum input power.
I would also never drive a liner to its maximum power as this can lead to destored audio on RX and also nasties to do with signal width.

you are better off using a realy good antenna than a linier.

[ryan_paul]

Sorry re read you post and I realised that I have not fully answered you questions.

A Linier works by using transistors or valves to aplify the input from your tranciever.
You could think of it as an exteral PA stage.
If the linier is a 500 watt I guess its probably a Valve amp.

If you go down the Linier rought make sure it has an inbult low pass filter.

500 watts is a lot, more that a full ham license holder can use without a NOV or a dogy argumant about coax loss HI.
If you use 500 watts you will need a very good ground plain and if its in you loft I would be a bit conserned about arc over from antenna to anything conductive.

[Panteneman]

Greetings,

Using a linear on a DV27 in the loft would be total insanity. Stray RF would be bouncing all over the place interfering with anything that is TV or Radio in the house, not forgetting neighbours.

It's best that an outdoor antenna is used, that is properly grounded and away from other people's TV antenna's as you can possibly get. Also, bear in mind that loads of TX power won't get you anywhere if the propagation is poor and the band is dead. Quite often, silly amounts of power aren't necessary when conditions are right. On 11m DX'ing from home, I have never used anything over 25w and worked most of Europe with no problems at all.

[68OD636]

So is it possible I'll maybe be able to work England & Scotland without a linear at all?
Really stuck for twig space, would maybe a Firestik or a Modulator be better?

[Keyboard]

If you want that kind of performance, there's no shortcut - fit an external antenna. There's no point trying 500w in your loft - it will be a world of pain and disappointment.

[jazzsinger]

How much power can realistically be put into a DV27 on a ground plane in the loft?

about 50 watts max.

How does a linear work?

previously answered by ryan paul

If you had say a 500w linear, would your output be a genuine 500w?

straight answer is highly unlikely,most manufacturers lie about the output power of their amps,conning the unsuspecting buyer,to get the quoted power levels you would have to overdrive the amp and the output would contain allsorts of harmonics and some are even riddled with harmonics below quoted input levels.harmonics are undesirable frequencies generated in linear amplifiers that are no longer operating in a linear condition,or can be also from the radio's power amplifier from the same condition in it and then reamplified by the external linear amplifier.exceptions to this are generally high quality amplifiers designed for the amateur radio market with built in low pass filtering,proper biasing and price tags that are frightening.these types of linear amplifier will usually give quoted power and a clean signal but are few and far between and very expensive.power is grossly misunderstood in the radio world and its effects highly overexaggerated ,but it can have advantages when used at the right times to overcome certain conditions but it will never compensate for a poor antenna.

as ryan paul and panteneman rightly say a better investment is a good antenna,which also has the added benefit of improving incoming signals as well as outgoing ones.

[ScotchEgg]

You'll be relying on the propagation more than your station, linear last. Sort out your antenna, SWR, earthing, modulation, radio. Then look at more watts.

Can you have an outdoor antenna?
ANY antenna out is better than one in. If you need to go low profile why not a wire dipole?
1/2 wave at 11m is under 17ft and can go horizontal for DX. Pennies to make

[ryan_paul]

Didealy you would use an outdoor antenna put as high as posible.
In the real world this is not always poisble.
If you cant put up an outdoor antenna you could try a beam antenna in your loft this will give you some more gain, a tipical 3 element beam will give you about 5-6 dBd gain.

the downide is that you will probably have problems rotating it.

cheers.

[ChickenMadras]

Get a good outdoor antenna.
Running power into a crap antenna is just pis*ing into the wind.

No amount of power will help the other dude get back to you. Linears only work one way. Good antennas work both ways.... Frankly, if you think you need 500w, then you are probably doing something wrong.

P.S. Do you have fire insurance for your loft ?

[68OD636]

Lol!! 500w was just a random figure to ask about power outputs!!

Unfortunately, I can't put up an external twig, so the post was really trying to see what my options were re getting out to Scotland & England - guess it's not possible with a loft mounted antenna?

[ryan_paul]

indoor antennas though not ideal can work.
I have worked lots of counties in europe on 20 and 40 meters with a doublet and well under 10 watts.
I put up an outdoor vertical and things were a lot easyer.

when I was into CB I worked a couple of counties with a dipole and 4-5 watts.

I would think that the main problem is the conditions on the higher HF bands at the moment.
however now is the time of year for some sporadic e and you could be well away