Echolink Node System Design

[Batman]

I'm looking for advice on the design of an echolink node. What is the best simplex moto radio for a high RF environment? I'm trying to maximize range. The antenna needs to be optimized for being high up on a hill(college hill) in easton, pa. I'm set on using heliax going to the antenna and LMR 400 jumpers. I going to employ a bandpass filter for 146.490. I'd like a system TPO of 100 watts at least. I also want to use not only echolink but a simplex autopatch as well.

I'd like advice from the experts on how to best accomplish this setup while keeping costs down.

[rrfd43]

I have used a Maratrac VHF for over three years now. I made a home-brew interface to the computer- opto-isolator for the TX and isolation transformers for the audio. The head unit is a 99 channel version sitting next to the computer on the desk. It runns a full 100 watts I have the radio mounted in a closet with a 35 amp astron power supply and a fan to keep things cool. This unit has run 24-7 for three years without any problems. Antenna run is LMR400 about 35 foot to a cushcraft 3 element vertical omni antenna. Range is ok, for portable, about 25 miles consistant for mobile, and better than 45 miles when the car is high enough to run it.

I keep timers on the PTT, recieve on echolink, and timeout of stations without activity. If you get any conferences to connect these cause a little concern do to the constant key-down time. A little work on your security and timer settings help to keep the radio safe, while not interfering with QSO's.

Audio is from the rear of the head. There are no issues with ground loop hum and I am commented on about the audio quality.

Hope this helps answer some questions if you need anything else let me know.

[Batman]

I was thinking of a 4 Bay Folded Dipole, 1/2-7/8 inch heliax, 100 Watt Amp, Maxtrac (i'm told these are excellent Rx on the ham band), Bandpass filter, LMR-400 for short jumpers. I'm not sure about implementing the simplex autopatch and echolink node w/o running into problems involving DTMF commands. I was wondering if anybody has tried running both a simplex patch and echolink. i've seen ap's on repeaters along side a echolink interface so i guess it's possible for simplex as well, just not sure about how it's done.

thanks for reminding me about the confrences and low duty cycle mobiles.

are there any continuous duty cycle simplex base or mobiles out there? Maybe cutting back the output on a mobile and adding a continuous duty amp on the output?

[rrfd43]

Can't help you continuous duty. Save yourself the time on a maxtrac and amp. The maratrac is basically a 100 maxtrac wrapped up in a trunk mount design.

Two run two different dtmf settings echolink has settings to have a dial prefix. For example set a dial prefix of pound, them echolink will disreguard any tones that do not strat with pound. I'm not sure on the autopatch, it could have a similar feature...

[Batman]

ah ok i did not get that deep into the settings on echolink. now only if someone would port echolink over to linux

[rrfd43]

Radios in the closet. Bolted to the wall and power supply below it...



Head units on desk with connections behind...