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HT1000 Parasitic Draw

Posted: Thu Jan 15, 2015 2:38 am
by buickid
Hello Batlabbers!
Just bought a HT1000, full DTMF keypad. Radio is in very decent shape, retired railroad radio. At first I thought maybe the battery I bought it with was bad, because I thought I charged it the previous day, and was dead when I turned it on the next day. Tried it with a known good NTN7144, fresh off the charger, known to last a day or more on my MT2000. Put it on in the morning, made sure the radio was off, came back in the evening and same thing, 2.5V, dead as a doornail. Has anyone heard of these Jedis developing a parasitic draw, and a pretty big one at that?

Thanks,
Trevor

Re: HT1000 Parasitic Draw

Posted: Thu Jan 15, 2015 11:39 am
by Will
Common problem. Most of the time it turns out to be a 'leaky PA' module which is part of the RF board.

One of the things we check on all portables serviced here, current draw when radio is OFF, measured in mili amps.

Re: HT1000 Parasitic Draw

Posted: Thu Jan 15, 2015 12:11 pm
by buickid
Thanks for the reply Will, I was hoping you would chime in. I'm guessing the repair is fairly involved. What would generally cause a leaky PA?

Re: HT1000 Parasitic Draw

Posted: Fri Jan 16, 2015 6:23 am
by MTS2000des
PA replacement is a relatively involved procedure. Usually the capacitors feeding the PA circuit go bad, sometimes the modules just fail. Could be a number of causes. In all honesty considering the age and relative low value of these radios, repair may not be economically viable.

Might be cheaper to find a replacement RF board from another HT1000/MT2000/MTS2000 of the same band if the particular radio is in great shape. Or just a replacement radio. I have bought MTS2000/HT1000's for as little as $10.

Re: HT1000 Parasitic Draw

Posted: Fri Jan 16, 2015 1:17 pm
by buickid
Thanks for chiming in MTS2000des. Seller agreed to take it back, so off to the post office today. Did a quick, slightly unscientific test last night. Got a battery eliminator and put my Fluke 87V inline. With the power switch off, and DMM zeroed to show 0mA with the battery eliminator regulator circuit idling, the HT1000 showed ~130mA, compared to my MT2000 and JT1000, which pulled 0.1~0.2mA under the same conditions. Back on the market for another Jedi!