Antenna Mounting

micko45

Hi All,

I usually build my own anntennas but due to lack of ATU on my yaesu FT0891, I bought a multiband antenna (no ATU for 40/20/15/10) from UK Antennas, but reading the instructions it says it should not be mounted on a metal pole.

https://ukantennas.co.uk/Instruction Manual.pdf?v=d2cb7bbc0d23

I didnt have anything else but a metal pole so wrapped it in duck tape and mounted it anyway to see what it would be like. SWR is fine but the static is high and the reception seems to be poor, could the metal pole have such an effect or is the antenna just junk,

Any ideas/suggestions?

micko45

micko45 wrote: »

Hi All,

I usually build my own anntennas but due to lack of ATU on my yaesu FT0891, I bought a multiband antenna (no ATU for 40/20/15/10) from UK Antennas, but reading the instructions it says it should not be mounted on a metal pole.

https://ukantennas.co.uk/Instruction Manual.pdf?v=d2cb7bbc0d23

I didnt have anything else but a metal pole so wrapped it in duck tape and mounted it anyway to see what it would be like. SWR is fine but the static is high and the reception seems to be poor, could the metal pole have such an effect or is the antenna just junk,

Any ideas/suggestions?

Those antennas get good reviews, they use 49:1 UNUN, I got 2 EFHW antennas, one is the myantennas.com EFHW8010, 40 meters long. Next is the hyendfednl 5 band MK III which uses a coil for 80m, bandwidth is very narrow but it gets me out on 80m and with a tuner I can work 160m which was a surprise.

These really are great antennas but you need to ground them well, 4-8 foot ground rod either at the UNUN or where the coax enters the shack is essential.

What's your SWR like on the bands it's resonant on ?

Both my EFHW are not noisy at all, however you could have some local noise from your house or neighbours if they are close. Get the antenna as far from any house as you can and height is key but as a ham I am sure you know about that.

My hyendfed.nl is attached to a metal pole ( with the supplied clamp for pole mounting ) without any issues, no SWR issues and no noise. I have it grounded before it enters the sitting room as this is where I mostly work JS8 Call.

You don't have to mount these antennas in a straight line either, you can have the UNUN close to the ground like my myantennas.com EFHW 8010 where I have it grounded, UNUN is about 3 feet off the ground, about half of the antenna then runs about a 90 degree angle to a 50 foot birch tree running South/North then East/West to a 65 foot Pine tree but it hangs down around 50 feet at the highest point, it's sort of an inverted L and it works really great.

All you have to do to add 40 meters of wire at some stage and you'll get 80/40/30/20/17/15/12/10m

You'd be surprised how much wire you may actually be able to fit in your property.

Any chance of some pics of your installation ?

micko45

My set up is pretty much a pole on end of the house tied to a tree at the end of the house, its dead straight. I am in the country so apart from popping of electric fences, static is usually quite low. I got years out of a G5RV which worked well until some cows ate the ladder line.

The instructions said no earth needed but you think it will make a difference to the high static?

As for the SWR, i put a meter onto the antenna and got the below, something is wrong with my setup. I have some time off over easter and will try to fix it.

7.1 -> 1.3
14.120 -> 1.3
accross the 10m band lowest is 1.8
accross the 15m band lowest is 1.8.

micko45

micko45 wrote: »

My set up is pretty much a pole on end of the house tied to a tree at the end of the house, its dead straight. I am in the country so apart from popping of electric fences, static is usually quite low. I got years out of a G5RV which worked well until some cows ate the ladder line.

The instructions said no earth needed but you think it will make a difference to the high static?

As for the SWR, i put a meter onto the antenna and got the below, something is wrong with my setup. I have some time off over easter and will try to fix it.

7.1 -> 1.3
14.120 -> 1.3
accross the 10m band lowest is 1.8
accross the 15m band lowest is 1.8.

Your SWR seems ok to me, you won't get a 1:1 SWR, your G5RV SWR for instance would have been way higher but fed with ladder line the losses would have been much less than if fed with coax.
Feeding a more resonant antenna such as yours or doublet with coax would have very low loss too it's only when you feed a non resonant antenna with Coax do losses become significant.

See what your SWR is in the middle of the Phone portion if this is where you want.

As for the static it depends what's causing it, is it local, ( house, ESB etc ) or is it atmospheric ? It can just come out of the blue if it's ESB related and it can travel significant distances but that would be more of a buzzing noise.

I've read that an antenna doesn't need to be resonant to be effective, your G5RV worked fine as too would a doublet fed with ladder Line. The clear advantage of the EFHW and 49:1 UNUN is that no tuner is needed for the bands it's designed for except to maybe flatten any small SWR that might exist.

The SWR looks fine anyway to me, the Coax acts as a counterpoise so if you haven't try lay some on the ground maybe 10 meters and see what the SWR is like after.

Grounding is essential to bleed off any static that might cause noise or damage your radio especially as we're coming into Summer when Lightning will become more common.

You can ground your station like in the below pic, use an 8 foot ground if you can find one or 2 x 4 foot and try bond them together somehow. You can water proof the connections with self amalgamating tape. The pic also shows lighting protection.

If you still have noise issues then see if it's static crashed you're hearing this can be picked up from hundreds or thousands of kms when there are big storms and especially when there are several storms at the same time.

Check out sat 24 https://en.sat24.com/en make sure you click the cog on the bottom right of the pic and select lightning.

Failing all that get a 12V car battery and connect it to the radio, knock off the power to the house via the main switch in the consumer unit and see if this makes a difference to your noise level.

Any update Miko ?