Our Ecomm guy came to me with an issue, the EOC has 2 HF radios they want antennas setup for, but they don't want the antenna's attached to the building (A IN PHOTO). They need 80 and 40m, and have a dipole they can setup, but it has to be ran off of the tower (B) .

The issue is, there is no way to run coax,or so they say, they have "fiber" (pink line) but I don't know what that means. They are tossing around an idea of putting an SDR in the building out there and a computer in the EOC to run it. Is that feasible? I have no idea how a link would work, or what is needed.

The lines they have are underground and will not allow any wires above ground between the 2 buildings. The pink line distance is around 300 feet. If they could run coax in the underground conduit, what would be the size needed?

BTW they have 2 kennwood 480sat's they bought for this.


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While you can remote nearly any rig, the idea of using an SDR is the best, and, arguably, the easiest approach.

Flex radios, while expensive, will probably pay for themselves in terms of the simplicity of installation and operation. You don't even need a PC, you can use a Flex Maestro remote control head. The fiber that they refer to is an Ethernet cable. With an Ethernet network between the building and antenna site, the Flex radio plugs into the Ethernet network at one end, and the Maestro control head plugs into the Ethernet network in the main building. And that's it! Unless you also need to provision tuners, amp's and whatnot. However even that is not difficult if you choose the correct products. Same for remote power switching.

Just as an example, I currently remotely operate an ANAN-8000 radio, BG7TBL GPSDO, KPA-500 amp and use an MFJ-998RT remote tuner. Everything I need at the operating location plugs into my remote PC: mic, speakers, headphones and PTT switch. The only thing that runs from the PC to the radio "room" (really just a pile of stuff ) is a single Ethernet cable. I can fully control all aspects of the operation except for 12V power switching and to do that I just need to go out and buy an appropriate network controlled power switching unit.

Do they have a climate controlled building or telecom shed at the antenna site for the radios and other ancillary gear?

Be prepared to be overwhelmed with answers. Again, you can remotely operate almost any radio, and there are several ways to skin the cat per radio.

I'd still go with the Flex stuff if you can get them to throw the dough.

If there's a telecom shed at the antenna, a Flex located there is the simple (and probably most effective) answer.  You could use a Maestro, an iPad (or iPhone) or another PC to use the remote radio.  If the hard wired network isn't available at the far end, I would bet the majority of my paycheck that a wireless link using good gear (i.e. Ubiquity) would provide plenty of bandwidth / low latency over that short distance.  Once the Flex is on your network, you can access it from anywhere (including off-site if you want - included with the v2 version of SmartSDR, or via VPN with older versions).  If you go with the mid-level radio, one unit can listen (but not talk) on both 40 and 80 simultaneously (the lowest end 6XXX unit allows for one receive antenna).  

It sounds like tuners won't be needed (resonant dipoles).  Wiring up some amps with a Flex is as easy as a USB connection + the coax.  I'd suggest reading up on the Flex community pages to see how some of the folks there have their systems configured for remote access / peripherals.

I will check on the climate control in the shed, I wouldn't think so, but I've been surprised before.

I'm in communication with the manager there to pass this info on, and ask the questions.

I think there is a pretty easy networking solution for the Elecraft K3, if they'd prefer a more traditional radio.  The Icom 7300 can also be remote controlled. None of the networkable/remote options are inexpensive, but with the restrictions you describe, those are the options.

If they want simultaneous operation on both bands, they will need some bandpass filtering on each antenna to prevent front end overload and mutual interference.

What ever network they create for this needs to be totally independent and not internet connected or else some idiot will go online and malware will crash your comms....

The TS-590S can do LAN based operation with the free Kenwood software (you need a PC at each end).  A plus is the internal antenna tuner is very capable if antenna matching is needed.

Nick

My local EOC wants the same thing. Nothing connected to the tower gets connected to the building.

They just got struck by lightning and injured a bunch of dispatchers.



An SDR will be easiest. Best bang-for-buck too, and as long as you have transport, you can run it anywhere in the building.