Update: Nine days and counting (down)

Well, only nine days until we take possession of our new house and I couldn’t be more excited! My intentions were to sneak some radio-time into the past few weeks and I almost succeeded. Almost.

New (to us) house

When I hooked everything up in my mobile station, I was getting a much lower than normal voltage value on the radio. Subsequent testing showed that the second battery system was putting out 12.8V (~14V while engine running) but the radio was reporting only 9.5V. I have the radio installed in the rear of the vehicle some 15′ (wire length) away from the battery. The immediate suspicion would be the length of the wire – voltage drop due to resistance. The wire is 0-gague (nearly 1/3″ thick) and its resistivity is ~0.3224 milli-Ω per meter, so voltage drop (even under high current) is negligible (compare it to 18-gague which displays ~20.95mΩ/m).

Once we are moved-in, I will take the time to further investigate this rather bizarre issue with the mobile installation.

Sound card interface prototype board layout

On the radio / electronics side of life, I’ve been busy redesigning my sound-card interface board. The objective of this project is to provide a (nearly) one-board solution which is capable of providing galvanic (electrical) isolation between computer and radio while offering PTT / CAT (Yaesu) control of the radio, along with automatically controlling the ALC via the ALC-jack found on some Yaesu equipment.

As this project progresses, it is my intention to enhance the interface board with an on-board USB sound-card to both simplify the end-user’s experience and to hone my design skills.

At present, the board houses a number of prototyping features which will not be found on the “production” version(s). This is done to verify and compare boards between PCB fabrication houses, checking tolerances and part fitment. I am doing this because I create all of my own parts in Eagle CAD using the datasheets for the components I will be using. I know that this is reinventing the wheel and that I could use already-existing libraries, however, in some cases I’ve had to create parts for components not-yet present in distributed sources. I have found that creating my own library has greatly enhanced my working knowledge of Eagle CAD and electronics design in general.

So for the next few days, we will be doing a more comprehensive boxing-up of our belongings, leaving little time or ability to enjoy my many hobbies. I’ll try to post more in the near future, perhaps with something of actual interest to some who skim my blog site.

Until then, ’73!

This entry was posted in General. Bookmark the permalink.

3 Responses to Update: Nine days and counting (down)

  1. SAM says:

    Hi James
    Great topic you have here ,im currently building a prototype for hf amplifier with a arduino mega 2560- that does CAT/CIV,ALC & PTT decoding for icom ,yeasu and kenwood .Would you be interested in giving some tips on how to send some commands to the yeasu using a arduino “maybe adding it to the yeasu ft xxx – library”i am not into coding but am learning as i go along …i have read all the other topics and all very interesting …keep up the great work and congrats on your new nest …


  2. George Simmons says:

    I had a similar problem with a dual band Kenwood that was not putting out the full power. It was pointed out to me that it was not getting full power(13.8). The recommended fix was to make sure all the power line connectors-be they power poles or Molex or something else- were soldered in place and not just crimped. That solved the problem


    • James says:

      Hi George,

      I will be sure to investigate the pins of the Molex(ish) connector of the radio and the supply line. I suspect there may be corrosion on the supply-side (something some IPA or a similar electronic contact cleaner can deal with).

      I may very well convert the connector type to Anderson power-poles when I re-visit the mobile installation. I’ve also been considering a boost-converter to help prevent “sag” with the engine off (campsite ops), so that would more or less necessitate/facilitate conversion to p-p connectors.

      Thanks again for the tip!

Leave a Reply

Your email address will not be published. Required fields are marked *