I think it's also designed that way because a big part of its target market are telecoms with oldschool traditional dual polarity dishes fed from waveguides (like a 4' to8' size 6 or 11 GHz Andrew), where they have two separate waveguide ports on the rear of the dish.
In a scenario upgrading an old PTP microwave system to a dual polarity 820C link the 820C would be mounted somewhere a few feet away from the rear of the dish and a few short distance flex/twist waveguides connecting it. It is a lot more bothersome for all-new builds than a single radio unit that has one cylindrical dual polarity port on the rear and can mount directly on the rear of a dish... Exalt ExtremeAir, etc. On Tue, Oct 25, 2016 at 8:23 PM, Steve Utick <[email protected]> wrote: > The 820C does have dual radios in it. But, it has two separate waveguide > interfaces on the radio. You can either mount the radio to a "Splitter" > that combines the two carriers using the same polarization, or an OMT which > combines the two carriers on alternate polarizations. Then you have a > circular adapter on the antenna so you can use both polarities. You can > see examples in the PTP820c installation guide at: > http://www.doubleradius.com/c.283276/site/stores/cambium/ > Cambium-PTP-820C-Installation%20Guide.pdf > > In particular, page 2-7 shows all the parts. > > > On Tue, Oct 25, 2016 at 9:44 AM, Ken Hohhof <[email protected]> wrote: > >> If it’s an 820C, isn’t that dual core, meaning 2 radios in one unit, no >> separate combiner needed? >> >> >> >> *From:* Af [mailto:[email protected]] *On Behalf Of *Bill Prince >> *Sent:* Tuesday, October 25, 2016 10:27 AM >> >> *To:* [email protected] >> *Subject:* Re: [AFMUG] UT Local Ceragon Installer >> >> >> >> Are the two radios mounted through an OMT or such? Did they happen to >> switch which one is V and which one is H? >> >> >> >> bp >> >> <part15sbs{at}gmail{dot}com> >> >> >> >> On 10/24/2016 8:06 PM, Sterling Jacobson wrote: >> >> Well, worst case scenario someone along the way f’ed up the hardware and >> I would need the same installer(s) to know enough to tell me I need a new >> part or whatever. >> >> >> >> They did take apart the mount and maybe even the antenna from the radio >> in order to shift it to left or right hand mount. >> >> So there is a possibility something happened when they did that. >> >> >> >> This link WAS working from the same mountain tower to a slightly >> different location about the same distance just on one polarity for over a >> year. >> >> Because of licensing, I had to have the radio pair removed, and moved to >> opposite locations, with some storage in between time etc. >> >> >> >> I’m going to be super pissed if something happened physically to the >> radios or dishes. >> >> But at the moment everyone working on it so far is too stupid (including >> myself) to know the difference between config/aim and hardware issue. >> >> >> >> I’ll still pay to have someone competent tell me that everything is all >> good except that I need a part fixed, IF they can discern that with >> confidence. >> >> >> >> >> >> *From:* Af [mailto:[email protected] <[email protected]>] *On >> Behalf Of *Ken Hohhof >> *Sent:* Monday, October 24, 2016 9:00 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] UT Local Ceragon Installer >> >> >> >> Misalignment will almost always affect both directions. Yes, on a >> licensed link the 2 directions are different frequencies, but not that >> different. >> >> >> >> What you describe sounds kind of like a bad radio, or a configuration >> problem. Like xmt power set wrong on one end, or a xmt frequency out of >> range of the diplexer. I’m not familiar with Ceragon ordering, but I >> assume they have different diplexers for different sub bands. >> >> >> >> >> >> *From:* Af [mailto:[email protected] <[email protected]>] *On >> Behalf Of *Sterling Jacobson >> *Sent:* Monday, October 24, 2016 9:45 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] UT Local Ceragon Installer >> >> >> >> That’s probably exactly what happened. >> >> >> >> They spent hours on it and were still way off on dB on one side only. >> >> That’s why I assume the other side is angled or rotated too far (dual >> polarity X-Pic). >> >> >> >> One guy didn’t even use the volt meter, just had someone read dB from the >> web page. >> >> >> >> They didn’t even ask for angles, degrees, nothing. >> >> Just all by supposed line of sight, no scopes, and not even binoculars I >> think. >> >> >> >> I wasn’t too happy about the whole situation, so I don’t want a repeat of >> that. >> >> >> >> It’s less than 10 miles across Utah Lake, one end on a leg on a tower on >> top of a mountain, the other on a smaller tower attached to concrete wall >> near the freeway. >> >> >> >> >> >> *From:* Af [mailto:[email protected] <[email protected]>] *On >> Behalf Of *Ken Hohhof >> *Sent:* Monday, October 24, 2016 8:38 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] UT Local Ceragon Installer >> >> >> >> Are these big dishes? Did you not get a well defined peak during >> alignment? Is the signal more than a couple dB less than predicted, like >> 20-30 dB low? You’re on a sidelobe. I’ve had experienced tower guys run >> into this. They tend to be stubborn and believe they can align a dish with >> a 1 degree beamwidth by eye, and then they spend half an hour trying to >> tweak the alignment to get an extra 1 dB when they’re 20 dB off. Once the >> signal starts getting worse, they go back the other way instead of >> continuing. Convince them to do a wide sweep, and they find the main >> lobe. You have to go through the valley to find the mountain. >> >> >> >> >> >> *From:* Af [mailto:[email protected] <[email protected]>] *On >> Behalf Of *Sean Heskett >> *Sent:* Monday, October 24, 2016 9:14 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] UT Local Ceragon Installer >> >> >> >> The angle of the leg shouldn't matter...at most you'd loose ~3db but it'd >> have to be almost at a 45* angle for that. (Chuck did a demo at one of the >> animal farm events) >> >> >> >> If you can get me remote access I can look at the config for ya. They >> are very un-intuitive to say the least lol. >> >> >> >> -Sean >> >> >> >> On Monday, October 24, 2016, Sterling Jacobson <[email protected]> >> wrote: >> >> I need to get my Ceragon link running, it's been forever. >> >> I think someone on this list had offered me their service local to Utah >> for this. >> I am paying for this, either by Job or by hour. >> >> If you remember offering, and it's you, or you think you would like to >> help, then let me know. >> >> I've got the link installed on both sides and configured, just something >> not lined up or configured correctly. >> >> The local guys I used originally earlier this year couldn't figure it out. >> And I think the mountain side link is not mounted true and needs a proper >> mounting on the leg, or hardware to mount it true, not on the leg at an >> angle. >> >> >> > >
