counterpoise antenna

SWLing and TX Forum, for everything below 30MHz...

Re: counterpoise antenna

Postby m0lsx » Sat Dec 05, 2015 11:01 pm

Howes do some lovely bits of kit..I often use a Howes dual width (wide & narrow) audio filter, which narrows the audio & cuts out some of the noise.
The original builders manual it can be found at..
http://www.wykeradio.org/yabbfiles/Attachments/ctu8_Instructions.pdf
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 4973
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: counterpoise antenna

Postby G4RMT » Sat Dec 05, 2015 11:15 pm

TN-C-S mains systems have no predilection to become 'live' if used for providing a ground for an RF system, indeed, the earth path provided is far lower impedance than using earth stakes. As I mentioned it's possible to set up accident; circulating currents which could provide a few volts worth of unwanted stuff on the line when referenced to something earthed in a different location - evidenced as hum bars or picture flicks on some TV sets, and perhaps some odd noises on audio systems that have poorly designed reference grounding. Using the water system is still a very common method of providing earth bonding for safety purposes. The Neutral bonding to ground at the consumer unit/intake panel means that almost certainly the water system will be connected to the PME by the various bonds plumber use to earth their metalwork - and of course any pipework in direct contact with the 'real' ground is a bonus. with plastic pipe so common, nowadays it isn't the guarantee it was but certainly in my house, the main water intake is buried , and extends the earth plane into my loft. In one building I work in frequently, on a pier, it's quite common for the earth to earth potential to vary by a couple of volts, inducing all sorts of nasty hums into audio and video systems connected at both ends. Using two baluns and a CAT5 link is a handy way of providing isolation.

I too am a firm believer (and user) of ATUs - for HF bands I have never had proper, resonant aerials, usually random lengths of wire strung up, and as you tweak the ATU, the signal strength really jumps up - making almost random wires into reasonable aerials. I have a nice commercial ICOM HF rig that can transmit anywhere, and an auto tuner. Wouldn't be without it.

It never occurred to me scanner users would think they needed one - just a wideband, or multi band aerial that doesn't need matching. Back in the seventies, one of my old friends, sadly not with us any longer, had a piece of disused railway line at the back of his house, and it was originally track circuited, so sitting on insulators. He removed the fishplates from a huge length either end, and for a couple of years had a VERY long, and very low dipole for top band, until they removed the track!
G4RMT
 
Posts: 912
Joined: Sat Feb 07, 2015 5:45 pm

Re: counterpoise antenna

Postby lhuchison » Sun Dec 06, 2015 10:36 pm

Thanks guys, i made up my patch coax today. all ready for the ATU.
Anyone use a site called Short-wave.info? A mine of info on any frequency found, location etc.
Icom IC-R8500 + SDRplay + Diamond discone
bhi DSP noise cancellation speaker . 10 meter long wire . 9-1 balun, Howes CTU9 ATU
User avatar
lhuchison
 
Posts: 41
Joined: Sat May 17, 2014 9:18 pm

Re: counterpoise antenna

Postby m0lsx » Sun Dec 06, 2015 11:18 pm

No, but I do keep an eye on...

http://shortwavedx.blogspot.co.uk/

http://www.doctortim.de/

http://irishpaulsradioblog.blogspot.co.uk/

And http://alfalima.net/ which is not what it was, but is still worth a look.

http://www.freewebs.com/ukdxer/
WHERE TO FIND FREE RADIO STATIONS


Most stations can be found in specific parts of the shortwave spectrum.

76 metres: 3900-3945/4010-4100 kHz:

This is popular with European pirates, especially in the evenings when skip is longer, and during the day in winter months. A regular is Laser Hot Hits on 4026 kHz.

52 metres: 5800-5840 kHz:

European pirates can also be found here, overspill from 48 metres. Not so popular recently.

48 metres: 6200-6400 kHz:

This is a prime area for the Euro-pirates, especially at weekends.

47-42 metres: 6400-6900 kHz:

Other pockets of pirate activity occur in this area ... in particular between 6400 & 6450, 6500 & 6600 and around 6700-6750. Stations often pop up wherever they find a clear frequency

43 metres: 6900-7000 kHz:

This area tends be mostly used by North American pirates, but is growing in popularity among Euro-pirates.

39 metres: 7500-7700 kHz:

Unreliable propagation means this band isn't widely used but some Euro-pirates can be heard here.

Others also can be heard on higher shortwave frequencies ... such as 9290, 12256, 15070 among others.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 4973
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: counterpoise antenna

Postby lhuchison » Tue Dec 08, 2015 12:35 pm

Howes CTU9 is now fitted. excellent ! works perfectly and is like new. very pleased.
Would have inserted an image but can't see how its done.
i've been scanning the uk light frequencies on FM. very interesting. i picked up some sort of college.
oh well, back to it.
Thanks all
Leon
Icom IC-R8500 + SDRplay + Diamond discone
bhi DSP noise cancellation speaker . 10 meter long wire . 9-1 balun, Howes CTU9 ATU
User avatar
lhuchison
 
Posts: 41
Joined: Sat May 17, 2014 9:18 pm

Re: counterpoise antenna

Postby m0lsx » Tue Dec 08, 2015 1:57 pm

The Howes is only for frequencies below 30mhz & will not work even on the low VHF light simple frequencies.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 4973
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: counterpoise antenna

Postby lhuchison » Tue Dec 08, 2015 2:49 pm

yes , the howes is only for the sub 30mhz. The uk light FM are a frequency i've just come across and find them good for scanning. i use a diamond discone for the vhf/uhf
Yet to find a pirate though!
Icom IC-R8500 + SDRplay + Diamond discone
bhi DSP noise cancellation speaker . 10 meter long wire . 9-1 balun, Howes CTU9 ATU
User avatar
lhuchison
 
Posts: 41
Joined: Sat May 17, 2014 9:18 pm

Re: counterpoise antenna

Postby m0lsx » Tue Dec 08, 2015 6:32 pm

Listen for Laser hot hits, they are on mostdays & weekends are normally busy around 48 meters 6200 to 6400khz..Plus there is the occasional MW station..
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 4973
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: counterpoise antenna

Postby KarlPease » Mon Mar 21, 2016 4:30 pm

As per my knowledge any base fed antenna without a counterpoise is in reality only half an antenna. Every antenna is about balance & half the antenna is the radiator & half the antenna is the counterpoise & if that counterpoise does not exist in a transmitters antenna, then the coax is used as part of the antenna system & that is why some fools think an end fed antenna needs a choke at it's base, it does not, it needs a counterpoise or it needs a choke at the correct point in the coax feed & it may need both.
KarlPease
 
Posts: 1
Joined: Sun Mar 20, 2016 7:16 am

Previous

Return to HF & Shortwave

Who is online

Users browsing this forum: No registered users and 1 guest

cron