Last updated: ...06.06.2017 11:25

The Middle Tennessee Amateur Radio Society is composed of Hams in Middle Tennessee who are dedicated to promoting amateur radio, providing public service communications and having fun doing so. Anyone interested in Amateur radio is welcome to join us.

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Schematics & Designs

MTARS Technical Committee 146.700 & 146.820


On or about the 16th of May Frank and Larry went to 10/70 to continue the ‘wiring clean up’ and the finalizing of the 12 volt primary control circuits.   We installed some conduit, both for wire protection and for tidiness

reasons.   Each of the two new batteries now has its own 25 ampere protective breaker (with remote indicating contacts for future telemetry purposes) and the two circuits culminate in a high current battery isolation switch that allows the selection of All Off, Battery 1 On, Battery 2 On and Both On. 


These improvements now allow battery service as necessary without having any loose wires floating around with the associated hazards.   As discussed before, we now have the ability to not only fully charge both batteries, we can also replace a battery, do cleaning or any other task without interrupting power to the repeater.   We can also do specific gravity measurements on the electrolytes now to verify quality of charge.


As many of you have already noticed, we are hitting 14.5 to 14.6 VDC each day around 11:00 – 12:00 Noon with discharge levels reaching down to only 12.4 to 12.5 in the evenings.   One more point that some may have noticed is that the daytime temperature in the building is sometimes running between 95 and 105 degrees during the hot days.  This is because I had what I thought  was a wise idea to place some insulation in the eves of the building last year to help contain some of the heat and make the environment more tolerable for Jess while we were working up there.   It worked but now it’s getting too hot and we must remove some of it to get the temps down.   I believe that we want to install a small 12VDC ventilation fan with a thermostat to run during high temp periods (when the most charging energy is available).   We can do this cheaply.


We have another trip scheduled to place a final piece of conduit in the building.  

 As always, if you have any questions, suggestions or comments, please pass them along to me  or Frank Denk.

 Larry K4WLO

04/04/2017 146.700

This afternoon, Larry (K4WLO) and I went up to the .70 repeater and switched over to the new batteries.   We still have to go up again and 'dress up' the wiring, but as of right now, everything that we can do with the equipment we have has been done.    With the 5th solar cell, the solar cells wired in series, and the new batteries, the system is charging much better than previously.    If you have any questions, I'll be happy to answer them.

01/2017 New 2m antenna has been installed at 100 ft.  Also the 70cm hard line is up at the site but not installed on the tower yet.

11/2016 146.700 Tower is replaced with Rohn 45G and new guides are installed.




Also looking into installing 70cm radio and also link antenna to M.T.E.A.R.S. System  for Emergency communications.

"Future plans possibly" to include a 220 repeater system, and a 6M system, A.P.R.S. linking.






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MTARS, P.O. Box 932, Tullahoma, TN 37388