Re: [IC-7000] Relay to control 12V power to IC-17000

Bill Boyer

They make battery isolator relays for the RV industry that are as rugged as a Ford starter relay, but made for continuous duty. I used one to power a large "10 meter" amp back in my younger years. 

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On Jun 24, 2015, at 08:37, Milo dma@... [ic7000] <ic7000@...> wrote:


With regard to the earlier comment about "QRP", while I have not done a scientific analysis of current draw, here is an anecdotal story indicating that not all "QRP's" are the same, at least with regard to the 7000.  When I first got my 7000, I wanted to try it out in the car and monitor 2 meter traffic on a 2-hour trip we were taking.  So I put together a 12v plug, set the power to 5 watts because I knew I could easily hit the repeater with that.  Everything was fine until I hit the mic button and blew the 20 amp fuse.  It is quite probable that I could have gotten away with QRP on CW or SSB, but apparently not on FM.

Some people have even used a delay on the relay to ensure there are no starting spikes.  Though I agree that you should be able to have the radio on without the ignition.  Maybe it should just be totally manual.  OR, spend a few bucks and get MFJ's power conditioner/booster which would be the ideal solution.  There are lots of possible ideas depending upon the level of sophistication needed, like an isolated auxiliary battery, etc.

Milo, KF5GCF


On 2015/06/23 7:44 pm, ""James Ray wrote:



If the relay is solid state then I wouldn't worry about it. When I use a conventional mechanical coil and contact relay, I place a reverse bias diode across the coil to dampen the reverse voltage spike when it drops out. Most relays have diodes across the coil in current cars.  Other items can require protection as well. The A/C compressor clutch has diodes on them in our two cars.

73 de KF7SLM, Jim

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Tuesday, 23 June 2015, 04:37AM -07:00 from "Bob Mueller bob@... [ic7000]" ic7000@...>:



Others have piled on why the 10amp is not sufficient.  If you're only running QRP, then it might be possible to use that relay.
The other thing I want to mention is to make sure that any relay is rated not only for the appropriate amperage, but also rated for continuous duty.  Relays that are used for engine crank, for example, are not rated for continuous duty.  You may burn up the relay.
--... ...--
Bob Mueller

On Monday, June 22, 2015 at 21:46 , D C _Mac_ Macdonald k2gkk@... [ic7000] wrote:



Yes, the 10 Amp capability is WAY inadequate.  I'd use a 30 Amp rated relay.
A big benefit of using a relay to activate this or any transceiver is that you eliminate the possibility that surges and spikes on the 13V line during starting will damage the radio. 
As long as you use at least #8 AWG wiring for both positive and negative supply lines, any voltage drop will be minimal. 
You could power the auxiliary relay through the accessory position of the ignition switch.  My preference would be for a separately switched line so that you COULD use the ham gear without having the ignition switch turned on.
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From: ic7000@...
To: ic7000@...
Date: Mon, 22 Jun 2015 18:42:44 -0500
Subject: Re: [IC-7000] Relay to control 12V power to IC-17000

The manual on page 137 calls for 30 amp fuses. I wouldn't use that relay.
On Jun 22, 2015, at 6:40 PM, RLN37 rln37@... [ic7000] <ic7000@...> wrote:

I have been offered a wireless relay to control the (nominal) 12V power to the IC-7000 in my car. The relay is rated at 10 Amps. Is that a high enough contact rating? I'd like to use it in my car, mostly for SSB operation, but sometimes 2m FM as well. Thanks for any thoughts or advice.
73 - Bob, K6KL





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