I have been trying to research different antennas for using with the 900 systems. So far I have come up with M2 and Cushcraft yagis as being some of the best for 900 trouble links. Can anyone here concur with these findings?
I have also been wondering about Hyperlink parabolic grid antennas. I don’t see much talk of 900MHz grids online. They make 15dBi and 18dBi grids; does anybody have any experience with these/advice? How do you think they would perform compared to the yagis?
For cell sites with a single AP deployment, would it be a good idea to use a 13dBi 120 degree sector antenna? Was told by some the gain is too high and the AP just creates more interference with itself. My experience says otherwise; just wanted to check with others. What high gain sector antennas would you all recommend, if any?
Also wondering if anybody has used bandpass filters with Canopy 900 gear? what type/results? Are they worth it, or does canopy naturally handle out of band interference pretty well?
We’ve had very good luck with the M2 antennas. We shopped around a lot when we first started, but have settled on three antennas for 900MHz: The stinger, which is our default antenna, the M2 14 if that doesn’t cut it, and the 17 if the 14 still doesn’t get it. We’ve gained enough experience that we pretty much know from the survey which one we’ll need.
We have not tried any grid antennas for the 900MHz band.
As for the gain being too high, it isn’t hard to operate outside legal limits if you’re not careful, but as long as you’re not getting multipath reflections with enough delay to intrude on the recieve part of the cycle, you shouldn’t see trouble on the AP side from too much power. On the SM side, though, make sure you balance the power levels of the SMs. If you’re not familiar with that concept, see this post.
We have not used any bandpass filters. Our problem is noise IN the 900 band.
We used a handful of the 15db 900MHz grid antennas from Hyperlink. They were a pain to work with due to HPOL and I didn’t see any better results than I did with the 13db yagis from Hyperlink.
We’ll probably be switching over to just M2 for our higher gain needs to simplify inventory and ordering.
For 14db yagis I swear by the Cushcrafts. They are a welded construction, with a pigtail on the N-connector which makes installation easier. Very solid antenna and I’ve compared it to a few others and it beats them every time. They are about 100 bucks a yagi or thereabouts.
Just last week we tried a 17dBi M2 and while it was not welded and did not have a pigtail or very good (in my opinion) mounting method, it really improved a link that had degraded due to interference. I gained 7dB and the jitter dropped from 6 to 2. Awesome antenna. My main gripe is the mounting method of a single ubolt but my installer and I figured out a method of using a backer plate to directly bolt the yagi to, and then this allows two ubolts to be use to secure the antenna to the mast.
Being that the Cushcraft and the M2 is about the same price I am contemplating on just using 17dB antennas on each install and only using the 14’s when we are forced to (but only if the 14 will work). I balance the power levels on the AP’s anyway so that is not a concern.
The M2s have improved several of my fringe customers. Great antennas, but the N Connector and the mount are terrible.
They need a pigtail…
We have tried the 13 db grid antennae. They receive pretty good but transmit poorly. We ended up taking down the few we have put up.
In our hilly terrain we have made the 17 db M2 yagi our standard.
They transmit better than they receive, however, they have given us the best performance for NLOS shots.
You are right, they do need a pigtail.
My techs take the loops off and make the water-tight connection to the radios in advance. When they get into the field, they slide the yagi into the loop and mount.
It is not perfect but it works and cuts down on the time in the field.
Rculp, thats how I instructed my installer to weatherproof the N-connector. Remove the feed and weatherproof it first, and then slide it into position.
Some day when I get time I will do a side-by-side comparison between the Cushcraft 14dB and the M2 17dB using our Anritsu analyzer.
We have relied heavliy on the Cushcraft yagis as well. As stated before, well made, perform well, and you get what you pay for. Ive compared the Cushcraft the Pac Wireless 15dbi yagis and will never buy another Pac Wireless yagi. The Pac Wireless grids are okay. However, soon we maybe selling some like new Cushcrafts for a good price. Ive switched over to using Arc Wireless panels with excellent results. Enough that I may not stock only but a few Cushcraft yagis in the future. In some cases the power level maybe a little worse with the panel but link tests in some cases improve (better F/B ration). For half the price and a fairly ice proof antenna, its a win win situation. They are not made as well as a Mars panel, the mounts are not as nice as the Mars mounts, but they perform better at half the price.
How well would you say those panels work compared to the yagis? Better than the integrated Motorola SM’s antenna?
I have 2 Antel rwb 80014-120-5-25 900 antennas for sale any interest???
Thanks for the replies!..
Anyone try Astron or Moonblink yagis?
Let me preface this post by saying I love Moonblink. Daniel over there is awesome. Their prices are great too…
But their 17dBi yagi is major weak sauce… That is why I was so hesitant to try the M2 17dBi. I get better performance from a PC903 Cushcraft yagi than I do their 17dBi. Plus, I do not like the fact that the elements are just punched into place, and not welded or bolted.
The upside: Their feeds have pigtails with N-female’s, the feed is pre-attached to the antenna, and the mounting hardware is two u-bolts vs M2’s single u-bolt.
But again… I like moonblink.
We install a right angle street elbow on the M2’s and weather seal them in the shop. That has helped in the field too.