newbie power question

ullbergm · Post by **ullbergm** » Mon Jun 21, 2004 4:54 pm

I've got a newbie question for you. I'm installing a ham radio in my car and i want to put a switch so that i can toggle power between coming from the ignition controlled to the constant on. Is it as simple as putting a SPDT switch or would there be issues right when you actually hit the switch?

One obvious issue, that is leaving the radio on even thou you didnt mean to.

I know i've seen some timeout devices but now i cant seem to find any. Any suggestions as far as brands go?

Thanks a bunch.

mancow · Post by **mancow** » Mon Jun 21, 2004 5:41 pm

Tap the appropriate lines and run them to each side of an SPDT switch then hook the radio hot lead to the center (middle) leg of the switch. One side will select the switched line, the other will select the constant hot.

mancow

ullbergm · Post by **ullbergm** » Mon Jun 21, 2004 6:03 pm

mancow wrote:Tap the appropriate lines and run them to each side of an SPDT switch then hook the radio hot lead to the center (middle) leg of the switch. One side will select the switched line, the other will select the constant hot.

Ok, thanks. I thought it'd be that easy but i didnt want to fry my new mobile

c17loadsmasher · Post by **c17loadsmasher** » Mon Jun 21, 2004 6:04 pm

Inadvertantly leaving the radio on would be self-critiquing. You could make an indicator light to let you know that the switch is in the 'constant power' setting. Then there's always the battery-saver sort of method, where the B.S. unit will cut off power to the circuit attached to it when battery voltage drops below a predetermined value. I'm sure there are timers out there too that will turn off a load after a time. You could always wing it and just be attentive to what position you leave the switch in. Pack a pair of jumper cables.

Tom in D.C. · Post by **Tom in D.C.** » Tue Jun 22, 2004 2:54 am

Many of the newer cars have power takeoff points (they look like a cigarette lighter) which can be good for up to 20 Amps, depending on how it's wired and fused. My Outback has one in the back that runs my Icom 208 just fine. Makes life much easier and follows the status of the ignition switch, including having the power on to the outlet when the switch in the ACC position.

ullbergm · Post by **ullbergm** » Tue Jun 22, 2004 3:29 am

c17loadsmasher wrote:Inadvertantly leaving the radio on would be self-critiquing. You could make an indicator light to let you know that the switch is in the 'constant power' setting. Then there's always the battery-saver sort of method, where the B.S. unit will cut off power to the circuit attached to it when battery voltage drops below a predetermined value. I'm sure there are timers out there too that will turn off a load after a time. You could always wing it and just be attentive to what position you leave the switch in. Pack a pair of jumper cables.

the battery saver options sounds good, i dont really think that i'd forget it on, but you never know.. and the time i did leave it on would be the time i really needed the car to start, im sure..

Tue Jun 22, 2004 3:41 am

You can also purchase a "Chargeguard". They can be pre-set from 1 minute to 24 hours before the turn themselves off. We use them quite extensively here in my area with the local PDs. We set them for 2 hours so the cars can run the Vascar system, listen to the radio, etc. without burning fuel or having the ignition turned on. If you want, I can get you a price on one.

ullbergm · Post by **ullbergm** » Tue Jun 22, 2004 3:46 am

Station House Products wrote:You can also purchase a "Chargeguard". They can be pre-set from 1 minute to 24 hours before the turn themselves off. We use them quite extensively here in my area with the local PDs. We set them for 2 hours so the cars can run the Vascar system, listen to the radio, etc. without burning fuel or having the ignition turned on. If you want, I can get you a price on one.

Thanks. I knew i had seen some devices like that but i couldnt find them again.

va3wxm · Post by **va3wxm** » Tue Jun 22, 2004 4:48 am

Don't most newer ham radios have auto power off as a feature? My Kenwood TM-V7A is factory-set for 2 hours; my Yaesu FT-8900 is adjustable from 5 minutes to 3 hours.

Even if I leave the mobile on it'll turn itself off after the set time period.

No wires to cut, no fussing around.

mikerabbit · Post by **mikerabbit** » Tue Jun 22, 2004 6:05 am

Tom DC,
I have an Outback as well and was thinking of running a similiar set up with the rear power outlet. Do you get any noise bleeding in since its not a direct battery run?
Mike

ullbergm · Post by **ullbergm** » Tue Jun 22, 2004 6:25 am

va3wxm wrote:Don't most newer ham radios have auto power off as a feature? My Kenwood TM-V7A is factory-set for 2 hours; my Yaesu FT-8900 is adjustable from 5 minutes to 3 hours.

Even if I leave the mobile on it'll turn itself off after the set time period.

No wires to cut, no fussing around.

Good point, i didnt even think to look at that. I knew that HT's had it but didnt realize that they do the same thing on mobiles.. my d700 has a 3 hours timeout.

thanks

wa2zdy · Post by **wa2zdy** » Tue Jun 22, 2004 1:54 pm

All great suggestions to be sure, but if you leave the rig on, it won't run the battery down overnight. I've had different radios in the car and had no problem with a dead battery, except once I left the car for four days. Then it wouldn't start.

You may want to give it a try one night just to see before you spend a ton of $$$ on something you may not need.

Good luck.

ullbergm · Post by **ullbergm** » Tue Jun 22, 2004 2:20 pm

wa2zdy wrote:All great suggestions to be sure, but if you leave the rig on, it won't run the battery down overnight. I've had different radios in the car and had no problem with a dead battery, except once I left the car for four days. Then it wouldn't start.

You may want to give it a try one night just to see before you spend a ton of $$$ on something you may not need.

Good luck.

i guess they dont pull that much when they are in receieve..

thanks

c17loadsmasher · Post by **c17loadsmasher** » Tue Jun 22, 2004 2:31 pm

I beg to differ.. granted, a Maratrac and a Syntor are different beasts from the radio you have, but my fire chief has a Maratrac and it kills his battery if it's a busy night on the frequency. I used to have a Syntor X9000 in my truck, and it also killed the battery several times due to a busy night on the channel. I guess several amps for about 10 hours was enough to kill the battery. Better safe than sorry. It's a PITA to push the truck out of the garage so it can be jumped.

va3wxm · Post by **va3wxm** » Wed Jun 23, 2004 4:13 am

Good point. A hamsexy example would be the Icom 706 which is an absolute power hog on receive: something like 2-3 amps! Definitely wouldn't want to leave that thing on overnight.

thebigphish · Post by **thebigphish** » Wed Jun 23, 2004 7:39 am

c17loadsmasher wrote: It's a PITA to push the truck out of the garage so it can be jumped.

pull it in nose first, huh?

apco25 · Post by **apco25** » Wed Jun 23, 2004 10:55 am

Unless you have a weak charging system and or a crappy battery why would heavy use of either radio kill your vehicle battery?

I've never seen this problem unless you are trasmitting for hours on the batter with the car off.

c17loadsmasher · Post by **c17loadsmasher** » Wed Jun 23, 2004 2:41 pm

thebigphish wrote:
c17loadsmasher wrote: It's a PITA to push the truck out of the garage so it can be jumped.
pull it in nose first, huh?

Yeah... if I do that, then I can just walk out the door to the truck door. If I back it in , the door is on the other side. It's a tight fit

And in response to the weak charging system/battery....no, it was a brand new battery, etc. Never any problems since I took the Syntor out.

apco25 · Post by **apco25** » Wed Jun 23, 2004 4:47 pm

well in that case I'd have to say its a weak alternator that wasn't properly charging the battery allowing the syntor drain the charge.

c17loadsmasher · Post by **c17loadsmasher** » Thu Jun 24, 2004 2:12 am

Morons at the dealer said it was fine...cause that's what I thought too. (shrugs) It's fine now...not a lick of trouble since I took it out.

wa2zdy · Post by **wa2zdy** » Thu Jun 24, 2004 3:19 pm

No, true, the Syntor X draws over an amp with no received signal. Of course if you leave the audio loud it will draw more on a busy freq.

The original poster said he's installing a "ham radio." To me, that conjurs up visions of a little Kenwood or something. In the four day example I cited above, the radio was an Icom IC-3200A - a 1987 vintage 2m/440 rig.

Yes, we all agree, there are exceptions to the rule, and we know what most of them are (I use the Syntor X as an example only because I have one.) The norm for a "ham radio" will be very different.

And I didn't know about the IC706 drawng that kind of current on receive. That's pretty steep. Is that what the specs say? Geez.

I still say the original poster should just try it one night; with the car parked nose OUT! LOL.

ullbergm · Post by **ullbergm** » Thu Jun 24, 2004 5:10 pm

wa2zdy wrote:The original poster said he's installing a "ham radio." To me, that conjurs up visions of a little Kenwood or something. In the four day example I cited above, the radio was an Icom IC-3200A - a 1987 vintage 2m/440 rig.

This is a kenwood TM-D700, the specs says 1A or less on receive and a max of 11.5A when transmitting.

wa2zdy wrote:I still say the original poster should just try it one night; with the car parked nose OUT! LOL.

hehe,
I'll give that a shot, and ill try to remember to park it the right way.

wa2zdy · Post by **wa2zdy** » Thu Jun 24, 2004 11:44 pm

Well, I did a little research and wow, some of those radios DO draw some current while just sitting there. The IC706 specs do indeed say 1.8A on receive! That's a lot of juice for sitting doing nothing. And 2A at max audio output.

Geez.

I'll step back now and keep my mouth shut LOL.

ricciticcitembo · Post by **ricciticcitembo** » Sat Jul 03, 2004 6:48 pm

For what it's worth, I keep on a Spectra with a loaded scanlist
lashed up with the Saber Repeater at Max Power.

Only in the Dead of winter at below freezing, on a busy crime night,
does it kill the battery overnight, and even then only after 12 or more
hours. Maybe quicker if the Temperature is in the single digits, or less
than zero.....So the winter time is a little dangerous for the Battery.

In the summer, it's good for at least a whole day.
(vehicle gauranteed to start)

newbie power question

newbie power question

Vehicle power source etc.