Man pack radio grounding & antenna counterpoise

[B5496RR]

Hello,

I have a couple questions related to proper grounding of the radio and also the antenna tuner in my man pack rig.

Also a question related towards correct installation of the antenna counterpoise/radial for the HF antenna on my man pack rig

I currently have a ICOM-7000 and a IT-100 antenna tuner in an aluminum framed housing. Please see link - Radio Station Antenna Tuner Backpack Frame for Yaesu ft 817 LDG Z11 LDG Z100 Ham | eBay

I have done some research already but I’m coming up with conflicting data and honestly I’m a little confused, any help would be appreciated.

1) I currently have a 10 gauge ground wire from the radio ground lug to the framed housing and also a separate 10 gauge ground wire from antenna tuner ground lug connected to the framed housing BUT THESE TWO GROUND WIRES ARE IN TWO DIFFERENT LOCATIONS ON THE FRAME. Should both ground wires be connected to the exact same location on the frame? Is my current setup creating a ground loop?

2) When speaking of the antenna counterpoise/radial for my HF antenna (MFJ-1979 & MFJ-1899) I assume that the correct radial should be a length of wire extended from the framed housing extending outward away from the radio in a ¼ wave length per the particular band being use. Is it correct to say that the counterpoise/radial can extend from the framed housing or does it need to extend directly from the lug on my 3/8-24 adaptor (see link) or should it be connected directly to the radio and antenna ground lugs? NCG Antenna Mount Adapters AD-35M - Free Shipping on Orders Over $99 at DX Engineering

3) When using the complete rig indoors connected to my roof top antennas can I simply connect a grounding wire from my radio frame to a known good ground connection that connects to a buried ground stake outside of my home?

Thanks in advance,
KD8HVN
Ray

 

[prcguy]

Howdy Ray,
Your probably ok with the radio/tuner grounding since any short wires you made are a very small fraction of a wavelength at HF and everything is mounted to a conductive metal frame. Your base antenna should be grounded per NEC for safety and at that point there is probably no need to ground the radio in the house, unless your feeding an end fed wire against a counterpoise and then you would be grounding the tuner.

One thing to keep in mind is a single tuned 1/4 wave counterpoise with the vertical type antennas you are using creates an inverted V dipole with one element (the counterpoise wire) laying on the ground. A 1/4 counterpoise will have RF current on it and will radiate more than the very short inefficient MFJ whips, but your best radiator (the counterpoise) is laying on the ground and not doing you much good.

A ground plane with two or more equal elements heading out from the antenna in different directions will cancel radiation and will be more of what we think of as a counterpoise or ground plane. But that would leave only your MFJ whips as very short and inefficient radiators on the lower bands.

If you raise the single counterpoise wire way off the ground you will see an immediate improvement on the lower bands. If you use the MFJ whips on 10m or 6m where they are not so short and where locals would probably be using vertical polarity, you will get much better efficiency than say 20m and lower.

My main attraction in amateur radio is HF manpacks and small KX3 type radios in the field and I only use a vertical whip type antenna for 10m or 6m. If you study the use of HF manpacks in the military you'll find the supplied whips are almost never used except for testing or very short range. The military commo guys put up dipoles or end fed wires or inverted L's or something other than the whip antennas because they actually need to communicate.

I have a Maldol version of the MFJ-1899 (the MFJ is a copy of the Maldol and others) and its grim at best on performance. About the only place I've used it is at the Dayton Hamvention to check into the military 80M AM net with a KX3 on low power from the flea market. I only needed to communicate a 1/4 mile and it worked fine for that....
prcguy

Hello,

I have a couple questions related to proper grounding of the radio and also the antenna tuner in my man pack rig.

Also a question related towards correct installation of the antenna counterpoise/radial for the HF antenna on my man pack rig

I currently have a ICOM-7000 and a IT-100 antenna tuner in an aluminum framed housing. Please see link - Radio Station Antenna Tuner Backpack Frame for Yaesu ft 817 LDG Z11 LDG Z100 Ham | eBay

I have done some research already but I’m coming up with conflicting data and honestly I’m a little confused, any help would be appreciated.

1) I currently have a 10 gauge ground wire from the radio ground lug to the framed housing and also a separate 10 gauge ground wire from antenna tuner ground lug connected to the framed housing BUT THESE TWO GROUND WIRES ARE IN TWO DIFFERENT LOCATIONS ON THE FRAME. Should both ground wires be connected to the exact same location on the frame? Is my current setup creating a ground loop?

2) When speaking of the antenna counterpoise/radial for my HF antenna (MFJ-1979 & MFJ-1899) I assume that the correct radial should be a length of wire extended from the framed housing extending outward away from the radio in a ¼ wave length per the particular band being use. Is it correct to say that the counterpoise/radial can extend from the framed housing or does it need to extend directly from the lug on my 3/8-24 adaptor (see link) or should it be connected directly to the radio and antenna ground lugs? NCG Antenna Mount Adapters AD-35M - Free Shipping on Orders Over $99 at DX Engineering

3) When using the complete rig indoors connected to my roof top antennas can I simply connect a grounding wire from my radio frame to a known good ground connection that connects to a buried ground stake outside of my home?

Thanks in advance,
KD8HVN
Ray

 

[sloop]

Check out hfpack.com this site will tell you all you need to know to do back packing radios. I use a FT-817, MFJ 971 in an communications outfitters pack. I use it as my 'travel' radio.

 

[B5496RR]

Thank you for the help and detailed information!