Hi everyone, I am reaching out to ask for advice regarding HF radiated emissions immunity for Mikrotik gear. At our HAMWan site, we have three sectors (mANTBox 15s) and two dishes (mANT30PA with BaseBox5) in the vicinity (<10feet) of a multi-kW EIRP HF (10-15-20m) antenna. Since we have installed the HAMWan gear, the HF gear has been offline but I am worried that it will get damaged once we turn things back on. Mikrotik support did not have any information on this. Does anyone have any specs or practical experience to share? Any advice would be much appreciated. Thanks for your time! 73, Levente VA7QF -- Levente Buzas, MASc, EIT Laboratory Manager Propagation Laboratory Department of Electrical and Computer Engineering University of Victoria lbuzas@uvic.ca +1.250.818.3937
Hi Levente, Given the spacing, I suspect all that plastic-encased gear will suffer crashes or communication dropouts when the HF keys up. It's also likely that it's producing detectable RFI in the HF spectrum with such close proximity. Not sure if RFI on the RX side is important in your situation or not. The first thing likely to break under TX will be your Ethernet links. They are long conductors which couple well to HF, and their signaling can be affected by HF frequencies. At one of our sites, which is colocated with a medium power FM broadcast station, we had to switch to fiber to feed the modem with data. The PoE is thankfully surviving the FM signal, so we're dual-feeding it with CAT5 for PoE and fiber for data. This modem is also built inside a metal enclosure, with SFP and RJ45 ports available, so it was an easy fix. In your situation, it sounds like a harder fix, given everything is in plastic and the sector antennas are integrated with the modems. The mANT30 should do a good job of rejecting HF though. It's a waveguide feed with a subreflector, so there are no exposed dipole elements. The waveguide will filter out any HF. The dish modem should live in a metal enclosure though. If it doesn't need to support 5 or 10MHz bandwidths, then Mikrotik sells 802.11ac modems that are metal enclosed and feature SFP ports for fiber. If it does need to support 5 & 10MHz, there are these metal enclosures that can hold a Mikrotik PCB: https://rfelements.com/products/enclosures/stationbox-alu/stationbox-s-carri... They also have enough room to house some fiber conversion gear. I'd suggest the same for the sectors, along with compatible antennas.. Or just key up and see what happens. :) --Bart On 10/6/2022 10:29 AM, Levente Buzás wrote:
Hi everyone,
I am reaching out to ask for advice regarding HF radiated emissions immunity for Mikrotik gear. At our HAMWan site, we have three sectors (mANTBox 15s) and two dishes (mANT30PA with BaseBox5) in the vicinity (<10feet) of a multi-kW EIRP HF (10-15-20m) antenna. Since we have installed the HAMWan gear, the HF gear has been offline but I am worried that it will get damaged once we turn things back on. Mikrotik support did not have any information on this. Does anyone have any specs or practical experience to share? Any advice would be much appreciated.
Thanks for your time!
73,
Levente VA7QF
-- Levente Buzas, MASc, EIT Laboratory Manager Propagation Laboratory Department of Electrical and Computer Engineering University of Victoria lbuzas@uvic.ca +1.250.818.3937
_______________________________________________ PSDR mailing list PSDR@hamwan.org http://mail.hamwan.net/mailman/listinfo/psdr
participants (2)
-
Bart Kus -
Levente Buzás