Yagis: 900MHz vs. Ice Round 1

900MHz, 11dBi Yagi, 13dBi Yagi, 12dBi Integrated

Well, I’m sure this topic has been beaten to death around here, but I figured I’d share my most recent experience with everyone and maybe get a few people to gasp as they too remember their first ice storm.

So, we got some ice earlier this morning before dawn and it continued until about noon or so…The onslaught of problems were on their way, said a voice in the back of my head as I sat watching the Wunderground radar map in motion at 3AM.

In all honesty, it didn’t turn out too bad. A few people had some issues. The issues that they (we) experienced were periodic re-reg, drop connections, etc. By noon, I had already been in & out of the office on 4 separate calls; very frustrating.

I pondered how things turned out; I studied who had issues, their geographical locations and the conditions nearby them. I realized, and it’s quite funny to me, that people to the south of town far, far away (well, really ~10mi) had zero issues. People closer to town (~5mi) to the East, North and North-West had issues.

I question the fact that ice buildup actually causes problems on Yagis specifically. I have to question that ice on Yagi’s alone isn’t as harmful, if at all as harmful as ice in the trees. I noticed a few Integrated SMs that had troubles. They had NLOS connections with approx. 10-15% foliage, but averaged a strong signal in any other type of weather. I concluded their issues were from ice buildup on trees and other obstacles nearby.

It’s very interesting to look at my Prizm software, see the problem people (usually on a same sector) and mentally map out how the weather had moved across this county. My sector 2 (of 6) which points in a EastNorthEast direction had the most problems. There were problematic spots here and there on the north facing and north west facing APs also; but spotty.

I’m glad I rarely get storms like these around here; and I’m also glad that this being Ohio and the month of March, we can go from 70degrees to 30degrees in 1.5 days; such as this past week. So, this adventuresome day is almost over. I’m glad. I’ve learned a lot. It’s not so much “myth” for me anymore. I wasn’t 100% ignorant to the fact ice causes issues in any type of RF environment, but, I was on the more “confident” side it wouldn’t affect me like I’ve read/heard about it affecting other WISPs.

Well, Round 1 is over. Sorry if this was a bit off-topic and windy. I’m not going to go back and edit this, because frankly, I wrote too much. So sorry in advance for typos or incorrect information.

In 5 years we had never had a problem with ice.

February was one of the coldest in recent history out here in normally sunny California. We had some very very cold storms come through and ice up our AP’s.

AP’s facing west and northwest got the brunt and as a result, customers that were on the edge had reg issues. AP’s facing east and southeast were fine.

I don’t know how you guys deal with it.

Well, I setup service calls. We’ll inspect the equipment, as I know tomorrow will be warmer and everything will be back to normal.

rjk, same with us. We tell the customers to wait for the sun to come out and the temp to come up and it will be all right. We had 4 hours worth where 5 or so customers from one AP were down for the entire winter. 6-12" of new snow on the way, its funny to watch the users, they seem to have an increase in signal when it snows…anybody else witness this?

I’m trying to decide if radomes on the Yagis are really worth it. Ice storms here are pretty rare.

Does anyone have 900MHz Yagis with radomes? Real world experience feedback would be appreciated.


We have used Maxrad and Scala covered 900 meg yagis but rarely with the canopy system due to the size and low gain. The Scala is a better antenna but costs more.
http://www.tessco.com/products/displayP … ventPage=4
http://www.tessco.com/products/displayP … ventPage=1

$400 is a little too steep for me. I’ll deal with the ice in a different way. =P

What about strapping one of these to the yagi to heat it.

http://www.rachelsrobin.com/shop/index. … 1#longdesc

Put it on a switched outlet or better, a timed outlet. Turn it on, heat the antenna, ice falls off, turn it off.

Don’t know the effect it will have on performance but it’s cheap enough to try and fail. If it works, it’s an easy fix.

I have also seen thin 10 and 15 watt heating elements that you might be able to try out as well. I think it would be ideal if it were DC powered rather than AC.

I’ve thought about heat tape etc… thought about it anyway.

What about hot paint? :stuck_out_tongue: …>LOL

I had a thought last night again…what about the same stuff they put on non-stick pots & pans? Instead of spraying stuff on the yagis. I’m not sure what’s in the non-stick stuff and if it would interfere. It would probably wear out after so long anyway due to sunlight and other weather elements.

The non-stick stuff is called Teflon.

As far as I know there is only one antenna manufacturer that makes a teflon coated yagi, and that is Bluewave Antenna.

I ran into this issue last winter not with ice, but with frost.

As far as I know, there is no “off the shelf” teflon coating you can buy. Bluewave actually bakes the teflon coating onto the yagi.

These antennas are alot of money, but very much worth it if you have ice/frost issues.

Their regular blue anodized yagis are also a far superior product to the others out there…

Just my two cents worth…get what you pay for :slight_smile:

Those are nice antennas.

I believe that the USGS uses them around here at some of their monitoring stations. I’ve seen the blue-ish Yagis here.

I see the 10dBd run ~$60ish, but eBay has a few for $25. Probably grab it and do some testing.

I have not had issues with ice at the sm but I have at the AP. I have a site at about 9600ft that sees extreme weather conditions year round. I decided to try a 120 deg 900 antenna on a AP. with the first ice of the season performance dropped. Two previous winters without issues I decided that I would go back to integrated AP’s. After the next ice no issues. The integrated units produce enough heat to keep the ice from building up.

Just had another little sleet/ice storm…knocked out almost everyone on one of my sectors. Argh, glad spring is here (almost!).

We tried the teflon thing last year - it helps at lot at first but the UV breaks it down over time. The problem really is the ice plus the moisture. Frozen solid the yagi is not affected much. I’ve thought about trying rubberized paint like they use on moble home rooves… never done it, but ???