My BMW R1150 GSAA at Deals' Gap

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Entries in Pelican 1200 (2)


The Comms Box - Catching Waaaaay Up

Wow, it's already mid-August and I failed big time in documenting my efforts from much earlier in the year when I built the comms box for the KLX250S. I won't go into great detail on the construction steps in this posting, but following the mounting of the Pelican case to the rear rack, I

  1. Completed wiring up the radio, intercom and power distribution inside the case
  2. Completed connecting everything up wiring and wiring it to the bike
  3. Was hugely disappointed about the amount of alternator noise on the radio's transmit and receive audio(!)

Here are some pictures showing the construction efforts that went into the comms box.

Autocom and Yaesu radio mounted

Underside wiring - What you don't see

Where the wires will come out

Looks pretty clean

NMO-style antenna mount

Modified commercial PTT switch for the radio

I'd previously tamed some alternator noise on the GS by adding a 20 Amp DC Line Noise Filter from PowerWerx, so I ordered one up for this application and tried it out. It DID tame the noise on the receive audio through the intercom, but it didn't help at all on the noise that impacted the clarity of my transmit audio. So, after a brief period of head-scratching, I decided that I was simply asking too much of the little KLX250S's electrical system. I decided to go "off the grid" and go to a solar-charged, battery-only electrical system for the comms box.

Out came the DC relay that I'd use to switch electrical goodies on and off with the bike's ignition. That in itself didn't free up enough room for a battery inside the Pelican case, so I created a bracket to secure the battery to the top of the case. The battery is a 12 Volt, 5.1 Amp-Hr. sealed unit purchased from Batteries Plus

An Instapark All Black 5 Watt Mono-Crystalline Solar Panel was ordered up from Amazon. After a protection diode (1N5817) was added to the panel, a pair of aluminum brackets were fabricated to mount the panel above the battery and to the top of the case.

Simple brackets holding the solar panel and battery

Wiring details - no place to hide!

Another view of the 5 Watt solar panel

The Garmin and Yaesu head unit up front!

With everything mounted securely and wired, I'm able to say that the "off-the-grid" solution works as expected, with no electrical interference from the KLX250S. I decent sun, the solar panel extends the use of the radio, GPS and intercom well past the typical day of riding. An auxiliary power connector makes it simple to plug in for an overnight boost charge, too.


The "big" little comms box project is started

Time to catch up on some writing! It's a rainy day here and I've already made quite a bit of progress over the past couple weeks building up a communications box for the back of the KLX250S. This part of the overall project focuses on doing what I'd done years ago on our BMW R1150GS Adventure, but this time do it MUCH better. The idea is simple: Create a reasonably weather proof environment for a dual-band amateur radio and intercom. I already had the following items:

  • Yaesu FTM-10SR VHF/UHF Dual Band FM Transceiver
  • Autocom Pro-7-Sport Intercom
  • FZ-1 power distribution block

The Yaesu FTM-10SR is weather proof transceiver made for motorcycle use. The 10 Watt VHF/7 Watt UHF transceiver is the little brother to the FTM-10R which shares the same head unit (display and control), but has a larger body containing the circuitry capable of transmitting 50 Watts.

The three items I expected to locate inside the comms box are show below.

After some quick measurements, I settled on a Pelican 1200 case as being just the right size to contain the intercom, radio and power distribution. Although I'd purchased the Pelican 1550 cases previously from the interweb, this time I spotted a local (to Raleigh) Pelican dealer with a storefront and made a trip over to see them. US Case offers competitive pricing on Pelican products and does a wide range of customization. Highly recommended!

From the start, I planned to bolt the Pelican 1200 to the new rear rack. After deciding to orient the case's hinges towards the back of the bike, I settled on a position on the rack and used it to mark the case for drilling.

Holes were drilled and hardware procured. I used some rubber grommets as a form of vibration damping between the rack plate and the 1200.

After a quick check that everything fit, it was time to bolt and rear rack plate back onto the KLX250S and then bolt up the 1200 on top. This proved a bit challenging due to the limited space between the rear rack place and the plastic fender underneath. My fingers didn't fit well in there to position the washer and nut on each bolt! With a little help from Elizabeth I was able to make this work and was happy that bolting and unbolting was not going to be a common activity once everything was assembled. Pictures below show the empty 1200 bolted in place.


Below is a picture of the working space inside the case. The real fun was about to begin!

I wanted the radio, intercom and power distribution to all be mounted solidly inside the box, so a sheet of 6mm thick expanded PVC from Budget Robotics was selected. This easy to use material can be drilled, cut and sanded without much trouble.

After some measuring and experimenting with a paper template, I used a router table to "mill" the sheet to size. A table saw would have worked, too, but I don't have one. Here's the base after sizing and drilling for mounting on stand-offs inside the 1200.

I'll cover the mounting of the radio and intercom, along with all the wiring in a future post to break things up a bit. Besides, my coffee cup is empty and it's time to top it off again.