MFJ artificial ground / counterpoise For sale is my mfj conterpoise, i dont need it anymore becuase i have laid an extensive earthmat under my raised vegetable beds and chicken run. here is something i found on internet.
How's your RF ground in your shack? Do you have RF "hot spots" that "bite" you when you transmit? Do you have RF feedback that causes your rig to quit working on some bands? Do you have TVI/RFI that makes your neighbors hard to live with? Do you get weak signal reports because of extreme ground losses or radiation pattern distortion?
These problems could be caused by poor RF grounding, especially if your rig is on a second floor with no ground at all. Even if you have a good ground, a long connection wire can ruin its effectiveness by isolating a true RF ground from your rig.
The MFJ-931 creates an artificial RF ground! It resonates a random length of wire thrown along the floor and produces a tuned counterpoise. This ground effectively places your rig near actual earth ground potential even if your rig is on the second floor or higher with no earth ground possible. Also, the MFJ-931 electrically places a far away RF ground directly at your rig -- no matter how far away it is. It reduces the electrical length of the ground connection wire to virtually zero by tuning out its reactance. The MFJ-931 connects between your rig and a random length of wire or a connecting ground wire. Its tuned for maximum ground current using the built-in RF ammeter. The MFJ-931 Artificial RF Ground covers 1.8 - 30 MHz and measures a compact 7.5W x 3.5H x 7D inches.
It cost £130 quid new but I am selling it for £50 quid collected from wolverhampton or posted at cost.
Re: MFJ artificial ground / counterpoise Hello FB220, how does this unit connect to the transeiver? does it go between the set and the tuner with PL259 connections?
--- Patrick - MFW / 68 FB750
kenwood TS870s - Astatic 1104c Microphone - 54 meter long doublet - Multiband Delta Loop.
Re: MFJ artificial ground / counterpoise Ah well not to worry, well done getting it sold anyway. My antenna is a balanced antenna all the way to a tuner anyhow so it probably would not have made much difference here using an earth.
--- Patrick - MFW / 68 FB750
kenwood TS870s - Astatic 1104c Microphone - 54 meter long doublet - Multiband Delta Loop.
Re: MFJ artificial ground / counterpoise Yeah its better when used with a long wire.
You connect the ground on your rig to the ground on your atu and then to the artificial ground.
Attatch a long piece of wire or a suitable lump of metal and tune the ground for maximum current like you would your aerial.
It cuts out a lot of static.
Its no real substitute for a length of wire connected to an 8ft earth stake hammered into the ground.
Sorry for the short reply earlier but I was off out !
