20 or 25 or ?

Hopefully tomorrow morning my #1 son and I will begin installing buried radials for my Hustler 6BTV, we are phasing out grass in favor of xeriscape and a few beds for veggies so there won't be much grass to cover the radials soon. I plan on installing 30 radials though I could install 40 were it worthwhile.

Question - I've seen new recommendations that radials be as long as the vertical is tall mine is about 25 ft other folks here have recommended 20 ft long. How long should the radials be?

 

Check http://www.w0btu.com/files/antenna/Optimum_no_of_radials_vs_radial_length.html and the link to N6LF's site there.

 

I have a 6btv and have 30 radials on it, buried about 1". Have 2 cut 1/4wave on each band and the balance cut for 1/4 wave on 20 meters. Works very well all bands. It's all a compromise between how much space/wire/time/strength/patience you have.

 

Completely pointless doing them to lengths of 1/4 wave when they're buried because the ground detunes them.

Put in as many as you can as long as you can in as equal a pattern as you can.

 

Go with the 25 footers and forty of them if you can.

 

If possible don't bury them use lawn staples for radials sold on eBay cheap and cut grass short and lay them they will disappear by next summer. Raised radials are the best and you need very few of those. I have 48 at this time stapled 1/4 wave length for each band covered radials cut for my 10-80m vertical with 6 8' ground rods I plan to increase to 64 total. The more radials the lower your take off angle to a certain point.

 

Use as many radials as you can as long and straight as you can, but anything over 40-50 radials or over 50 feet long is a waste. It is also wasteful to use 1/4 wave radials on multiple bands when they are in soil contact or near the earth. just make them whatever length fits and don't bother interleaving shorter radials. interleaving short radials with long is a waste of time and wire.

The 20 foot thing, or 25 foot thing, is not real good for 80 meters, but just do the best you can.

There is a myth that radials are tied to the height of the radiator. They are tied to the operating frequency, not so much the physical height.

73 Tom

 

Amen! Cover your yard as best you can.

 

BTW, the biodegradable plastic lawn staples from DX Engineering are great. They are large and are made to be pushed into the soil using the palm of your hand. I place one for every 5' of radial wire. $16 for 100. Buy some extras to use when radials ends pop up. In a few months the lawn will have grown over them. Completely.

For radial peace of mind install as many and as long as you can. You will never worry later on that you didn't max out the counterpoise. I like to use stranded green #14 THHN wire (from Home Depot, $45 for 500').

For 3 dB more signal and more bandwidth on 80 meters replace the RM-80S resonator with an RM-40 and a DX Engineering top hat. The 48' spokes are the ones to use.

The next step is to add an amp.