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.
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.
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!