Counterpoise question

#1
I've always been told that a counterpoise is used when the ground is dry and as a result earthing is poor...... (the couterpoise is spread on the ground under antenna)

BUT...

I've also been told that a counterpoise is used to create a reflection to stop groundwave being absorbed into the earth and it should be pegged using non metallic pegs just above ground level?

Any ideas and how often do you use them?

Cheers
 
#2
bibo_boy said:
I've always been told that a counterpoise is used when the ground is dry and as a result earthing is poor...... (the couterpoise is spread on the ground under antenna)

BUT...

I've also been told that a counterpoise is used to create a reflection to stop groundwave being absorbed into the earth and it should be pegged using non metallic pegs just above ground level?

Any ideas and how often do you use them?

Cheers
They shouls be used always as on average they give an extra 3dB of power/gain.
 
#4
bibo_boy said:
Cheers, but are they an earth or a reflector?

Do they sit on the ground or insolated from it?
They sit on the ground and aid the ground plane of the antenna, god it's a bit early for this!!! 8O
 
#6
IIRC there was also a counterpoise antenna that came with Larkspur manpack (A40?) - a kind of trailing wire that went the length of your body and tucked into your puttees.

(But then it was a very long time ago....)
 
#8
Polar69, yes.
 
#9
All antennas have two parts. A basic antenna is created by taking a wire/feeder and spliting out the two wires so they don't balance each other (think of a 1/2 wave dipole - if you put each arm alongside the other, twisting them together you've now got a feeder).

When you have a manpack set, parts of the radio itself act as the other part of the antenna.
With some VHF antennas such as the GSA people used to piss on it to improve the conductivity (hence power) - (hence the warning not to in official pams)
 
#10
polar said:
All antennas have two parts. A basic antenna is created by taking a wire/feeder and spliting out the two wires so they don't balance each other (think of a 1/2 wave dipole - if you put each arm alongside the other, twisting them together you've now got a feeder).

When you have a manpack set, parts of the radio itself act as the other part of the antenna.
With some VHF antennas such as the GSA people used to urine on it to improve the conductivity (hence power) - (hence the warning not to in official pams)
My bold, try to avoid doing this when Txing....
 
#12
IIRC the counterpoise "legs" should be equal to or greater than the length of the Ae legs in an ideal situation.
 
#13
Bibo, try and get a copy of the Radio Systems CD from Blandford. Its got a pam on their about A&P.

Also try to get hold of the Commercial Radio Techniques pam, it talks about many of the systems we use (e.g. AIRWAVE). (For some reason its not covered by any TA course)

Lastly their are two A&P pams, the one I mentioned above is for class 3 operators. The other one is aimed at the troop commanders course (comd group), see if your PSI /YofS can get you this aswell.
 
#14
devilish,
when was the last time your lot used a counterpoise... In fact when was the last time you got comms in ;0)
 
#15
roadster280 said:
Polar,

There's A&P, and there's A&P. Similarly, there would appear to be CRT and CRT.... all taught by Radio Systems Group, depending on whether the students are ops or techs.

CRT was a term invented by the God of Radio, Mr Mike Watling. I'm sure he's retired now, but around the turn of the Millennium, it was he and I that taught A&P and CRT. The reason CRT wasn't taught per se to TA, is that there was a specific course (run 2 or 3 times a year) for MOULD, which in those days was pretty much the TA's bag. I don't think any regular unit had it. TETRA used to be briefly covered, but in no great detail in my day. I'm sure it's changed now.
Ohh, Mould and MIV's now that went by the mid nineties didn't it?
 
#16
Its changed its name and is still a useful system. TETRA has similar problems as mobile phones, hence the need for plan B. (I don't believe Commercial Radio courses are now available including AIRWAVE)
 
#17
Mould HTS's were deffo still active mid 2000. That was the last time I used one. From what I remember they were due to be turned off in 2001. As for the MIV's.. Still got them just some different kit in the back now.
 
#18
fatcakes said:
devilish,
when was the last time your lot used a counterpoise... In fact when was the last time you got comms in ;0)
lol, point taken. As for getting comms in, that's Nokia's responsibility is it not?

And I think you will find that ourselves and our northern breathren managed to get a 30km link in last year(fcuk all to do with counterpoises, but a reason to brag all the same). :wink:
 
#19
has anyone improvised a mag mount adaptor for the masts or is their a issue one? i.e. a block of metal on top of a mast adaptor possibly with some straps for securing the mag moun

30k in scotland, when we last tried we kept getting sited at the bottom of the valley when last up there
 
#20
polar said:
has anyone improvised a mag mount adaptor for the masts or is their a issue one? i.e. a block of metal on top of a mast adaptor possibly with some straps for securing the mag moun

30k in scotland, when we last tried we kept getting sited at the bottom of the valley when last up there
LOL, not a chance up here mate, it was down south somewhere near RAF Lakenheath.
 

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