[MRCA] Todays M&S Net AAR

[Ray Fantini]

The mutt has two 550 CCA batteries that are a little over two years old wired in series. There is also a 60 ampere alternator driven by the engine that replaced the stock 25 ampere generator.  The generator sucked because it did not put out full current until the engine was running well above idle, the alternator always pumps out lots of current regardless of engine speed. 
With all the radios on in receive only the branch that feeds them is only drawing a little over two and a half amps, with the VRC-12 in transmit that draws maybe five amps more. With the GRC-106 in standby total current drain is only around eight amps or so and in transmit or tune will be drawing between twenty six to thirty two amps on the DC feed.
The two car batteries are rather small so they can fit into the battery compartment and may be undersize but you don’t need much in the way of batteries to turn over the little four cylinder engine in the mutt. 
The issue is do you need to keep the engine running for the entire time that you plan on transmitting? Or with good batteries are they well within the capacity of the batteries so you only need to run the engine only once every couple hours? Yesterday I was able to have everything running for over two hours just using the batteries but after that started to have issues. Anyone have any idea what the original military spec was for operating the 106 in a vehicle? If you were intended to keep the engine running the entire time you were planning on transmitting or not?

Ray F/KA3EKH
________________________________________
From: MRCA <mrca-bounces at mailman.qth.net> on behalf of Peter Gottlieb <kb2vtl at gmail.com>
Sent: Saturday, March 25, 2017 7:40 PM
To: mrca at mailman.qth.net
Subject: Re: [MRCA] Todays M&S Net AAR

Do you use the vehicle battery or a separate one?


On 3/25/2017 4:43 PM, Ray Fantini wrote:
>
> The goal was to take the M151A1 out of the garage, set up everything and
> participates in the M&S Net at noon along with attempting other QSO on
> different bands, also want to have everything ready for the Aberdeen event in
> May.
>
> Resources:
>
> Used the M151 just recently put back together after removing the engine and
> transmission to install all new seals and stop the never ending oil leaks.
>
> The AN/GRC-106 HF Transceiver, VRC-12 FM transceiver with vehicle mounted
> antennas were used in addition used the twenty four foot push up mast with an
> inverted V antenna cut for 5357 The on board antenna would be used for all
> other bands.
>
> Operation:
>
> Got everything set up just before noon. M&S Net went with out issue. No
> problems hearing or being heard by any participating stations. Did
> announcement about QSY to 18.125 after net and did. Did hear traffic at 18.14
> and 18.132 or so, did try calling CQ couple times on 18.125 but discovered
> that after a short period of time I was not transmitting. I discovered that
> when supply voltage drops too low the transmitter will not work properly.
>
> Things learned:
>
> Wanted to see how long I was able to operate without running engine. Did run
> the engine for fifteen minutes prior to beginning of M&S Net but not after
> that. By the time I started trying to work on seventeen meters battery voltage
> indicator was in yellow and now know that voltage indicator needs to be in
> green for proper transmission. The receiver works fine but the transmitter
> will not tune in low voltage condition. Next time need to run the engine more
> often or add external generator to mutt. Had the VRC-12 in operation entire
> time and was occasionally keying to see what effect that had on battery life.
> Where GRC-106 wont tune but still receive the VRC-12 still worked but at
> reduced power.
>
> May look into MEP-015 28 Volt Generator being I know where I can locate one
> that I can swap for my MEP-015 AC generatorand run all the DC stuff on the
> mutt from that located away from the mutt.
>
> Also noticed that there is lots of activity up on seventeen meters, perhaps a
> additional cut V can be prepared for that band. Also need to investigate
> getting RT-834 to replace my RT-662 being looks like if going to do anything
> on seventeen you need the pack R/T channel that’s at 18.157.5
>
>
> Ray F/KA3EKH
>
>
>
>
> ______________________________________________________________
> MRCA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mrca
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MRCA at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
MRCA mailing list
Home: http://mailman.qth.net/mailman/listinfo/mrca
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:MRCA at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html