Can anyone here recommend a good long-range cordless telephone? I've used the Engenius SN920 before, but honestly I was not able to get much better distance than with a standard cordless. I need one phone for a security guard that will be protrolling an outdoor area that's approximately 4,000 sq ft (1,000 ft from back to front / 400-500 ft wide). The area is mostly open, with some stacks of lumber in unpredictable places - approx 12 ft high). Line of site is very good over most of the area. The base unit will be placed in a small guard shack, and I can mount an external antenna if needed.
No. The power level is so low, and interference levels so high, on most cordless phones, that long range operation is not possible. I recently helped shut down an illegal high power 2.4GHz phone system running about 1 watt output. Despite the high power, the range was erratic in the downtown area because of severe interference from other system. 900MHz would have been worse. 5.8GHz might work until they too become upbiquitous.
I borrowed a pair of SN920 Ultra's about 2 years ago. It was really weird. Sometimes, I could talk easily between my house and downtown Ben Lomond, a distance of about a mile through a mess of redwood trees. However, it was totally unreliable. It would be working just fine and then just disappear. A few minutes later, dialtone would magically reappear, eventually followed by another disconnect. The
2nd unit seemed a bit better, but I had to return everything before I had time to try any long range testing.
However, 500ft radius coverage should not be a problem with this unit. It should have worked. Perhaps you had quite a bit of 900Mhz interference in the area?
A cordless phone is inappropriate and unreliable. What you want are licensed commercial radios on one of the "dot" frequencies. 1,000ft is no problem for these on either VHF or UHF. Surplus radios are cheap and commonly available. For 1000ft, two UHF HT's and rubber ducky antennas are fine.
Radio to phone patch interfaces are commonly available. For example:
However, you're not going to get full duplex operation to the telephone. The HT can only transmit or receive, one at a time. If you want something resembling good telephone operation, the base station will need to be full duplex. That means you'll effectively need to build a repeater at the base, which seriously raises the cost, and requires a different FCC license. The usual solution is to use a cell phone for telephone calls, and the two way radio for talking to a dispatcher.
Did the sn920 have an external omni? An old uniden 900mhz cordless became quite reliable and it was only pushing a 1/10th of the output the sn920 would.
We operate on a 10-acre site with widely spaced buildings. The EnGenius
922H (Duraphone-4x) gives us solid communications all over the 660 x 660, and all the way over to our two adjacent properties that are over 700' from the base unit.
The base is inside a metal-skinned prefab office, with no external antenna -- just the two rabbit ears that are stock on the unit. We're told that with a higher-gain outdoor antenna, we could roughly triple the range.
Sorry I didn't clarify: I've used the Engenius SN920 before, but *not* in this particular application. Perhaps it deserves a second look, considering the open space?
I'm sorry i did not clarify: I've not tried the SN920 in this particular application. I was hesitant to order one, simply because in another similar application I was only able to get clear reception up to approx 700', and I really need coverage over a lot that is 1000'-1200' at its deepest point.
I have, but the customer's primary motivator is getting the cordless phone to be part of their current PBX (a Nortel). They want any 911 calls to show their company name and address, and they want the guard to be able to receive phone calls that come through their system. They want the cordless phone to be an extension off their system.
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