EtherHam

Amateur Radio Over Internet

Random Wire Review 105: August 30, 2024

What radio for a long trip? New podcast mic setup. New ASL interface underway. ASL “restomod” project. XHDATA D-220 radio reviewed. Google Groups alternative. Zero Retries newsletter is recommended!

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Topics in Issue 105

1. What Radio(s) for Upcoming Road Trip?

2. Podcast Recording Combination

3. News: A New ASL Audio Interface Under Development by NR9V

4. Project: ASL/PC-1A “Restomod” Project Wiring

     4.1 Parts box
     4.2 Wiring
             4.2.1 Masters Communications RL-20 DB9 pins
             4.2.2 Microphone jack
             4.2.3 Audio amplifiers
             4.2.4 Capacitors

5. Review: XHDATA D-220 AM/FM/SW Radio

6. Alternative to Groups.io and Google Groups

7. Interesting Stuff: Zero Retries Newsletter

8. Grab Bag

     8.1 Allstarlink Notify (ASLNotify)
     8.2 Allstar Neo II
     8.3 Asteroid mining? Really?
     8.4 I flipped for this pocket knife
     8.5 Wirecutter recommends walkie talkies
     8.6 Wedding anniversary

9. Audio: Random Wire Reflections Podcast

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1. What Radio(s) for Upcoming Road Trip?

I’ve got a long road trip coming up at the end of September: Portland, Oregon to Wichita, Kansas. Currently installed in the pickup truck is a Yaesu FTM-300DR transceiver with a Comet SS680SB antenna attached to the roof rack. This is a 1/2-wave antenna for 2 meters and 5/8-wave on 70 centimeters. This combination has worked well for me. I hope to have enough time on the return trip to Visit Santa Fe, NM or Moab, UT again.

Map source: openstreetmap.org

Mounting an antenna on my Honda Ridgeline is a challenge. I don’t want to punch a hole in the roof. A mag-mount antenna would be okay but I know I’ll hit some very windy spots while driving, so a mag-mount is not preferred. I think the most likely would be a modified stake mount of some kind, with the mounting plate slipping underneath the tonneau cover that covers the truck bed…except unlike other light trucks, the Ridgeline doesn’t have stake pockets! I may have to use a carrier bar mount like I do with the Comet antenna.

I see there are several C4FM repeaters between Portland and Wichita, and since I like C4FM, I plan to use the FTM-300DR for this trip. (I’ll certainly need to add the Colorado Digital C4FM repeaters to the FMT-300DR.) I also run APRS while I travel.

My question is: what other radios/bands should I consider taking with me?

Eventually, I do want to move into DMR mobile radio but I have so much piled up on my “to do” list that I don’t think I can give a new DMR radio the attention it needs before the trip.

I like 6 meters but there are not as many 6-meter repeaters as there used to be. I’d consider adding a 6-meter rig for the trip. I do have a Yaesu FT-891 transceiver and would consider taking that to work 6 meters and some HF. I would like to mount an HF antenna on the truck and would prefer that it be adjustable while driving (i.e., an antenna for mobile use, not just portable use).

Potential HF mobile antenna options include:

I’m intrigued by the GRA-750B antenna, even with the “interesting” comments about it on the Amazon listing. I’m not a big fan of putting a screwdriver antenna out in the weather, year-round (it rains a lot in Portland!). The GRA-750B has no moving parts and requires a tuner. The manufacturer rates it for up to 120 watts on SSB and 40 watts on FM. It looks like it would fit on a stake hole antenna mount. You know, it might make an acceptable POTA antenna on a strong mag-mount or a tripod. Hmmm…

For a POTA antenna that I could mount on a tripod or on a hitch adapter on the truck, I’m liking a less-than-full-size delta loop antenna, the EAntenna HF Rotatable Antennas 17826.11B. Similarly, I’ve often wondered if I could build a poor man’s delta loop with a couple of 17-foot telescoping aerials with a wire clipped to the top of each aerial!

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2. Podcast Recording Combination

For the last several Random Wire Reflections podcasts, I’ve recorded audio using a Behringer C-1 condenser microphone running through a Behringer MIC500USB pre-amplifier. This week, I’m using an Audio-Technica AT2005USB dynamic microphone through the MIC500USB pre-amp. The AT2005USB also has an XLR connector and I’m using an XLR line to move sound from the mic to the pre-amp. The pre-amp has a USB out so that’s how audio gets to Audacity. I save the sound file as a project and edit audio in Audacity.

The AT2005USB has a cardiod pattern that does reject more background sounds than the C-1 condenser mic, at least when the sound is behind the mic. I think the sound with the AT2005USB mic through the pre-amp is just a little bit cleaner than I was getting with the C-1 mic.

I tested the sound and posted the results on the Random Wire:

As long as I’m talking microphones and associated bits, I purchased a new microphone arm for my recording studio, aka my desk. The FIFINE Microphone Boom Arm, Low Profile Adjustable Stick Microphone Arm Stand with Desk Mount Clamp, Screw Adapter, Cable Management, for Podcast Streaming Gaming Studio-BM88* swings out of the way, giving me a bit more room on my small sit-stand desktop surface.

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3. News: A New ASL Audio Interface Under Development by NR9V

David Gleason NR9V is creating a new audio interface board on a single PCB, called the UCI120 USB Communications Interface. This device will be suitable for use as an audio interface for an AllStarLink node. I am really excited about David’s project! His board will greatly reduce the time and frustration in building your own high-quality AllStarLink node. Impressive work by NR9V!

Find his software for AllStarLink nodes at https://allscan.info. When the UCI120 becomes available, I assume that’s where he will also publish product information. In the meantime, David is keeping interested folks informed via his Facebook group at https://www.facebook.com/groups/allscan.

About the UCI120, David writes:

The AGC/dynamics section will have a switch supporting 3 attack/release timing settings, a bypass switch enabling external mic-preamps/channel-strips/line ins to be used, a switch to support electret (e.g. headset) mics, and a jumper to bypass the low-cut filter, as well as to the mic gain adjust knob and 0/10/20dB mic boost switch. With these options the UCI120 will support pretty much every type of mic and line input, while also supporting many other applications e.g. recording, podcasting, remote rig control, and use as a standard PC USB audio interface.

Considering that the UCI120 “will also be available as the PCB only without enclosure so it can be used in comms speakers, phone patches, etc.” I’m tempted to delay my Kenwood PC-1A audio interface project! Since I already have my parts on hand, and because I want to extend my learning, I’ll carry on with the PC-1A build. However, when David’s UCI120 comes out, I’ll be one of the first in line to try it!

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4. Project: ASL/PC-1A “Restomod” Project Wiring

I needed a shorter name for this project so it is now the PC1ASL.

Previous project links include:

4.1 Parts box

My project parts box is not at all fancy — it’s a Plano tackle box that I picked up at a thrift store for a couple of bucks! I find it helps to keep the little bits and pieces together as I work on a project over several weeks.

PC-1ASL project box

4.2 Wiring

Below, I describe my thinking on how to connect the components together. I don’t have a good circuit design program so if a drawing shows up here, I probably did it on the back of an envelope in pencil, with lots of erasures! If there is no drawing, well, that means the pieces are still trying to come together in my mind.

This project revolves around the Masters Communications RL-20 audio board:

Master Communications RL-20 audio board

4.2.1 Masters Communications RL-20 DB9 pins

The following pinout description comes from Masters Communications for the DB9 pins on the board. (I think the proper term for this is a DE9. “The DE-9 D-sub 9-pin connector is often mistakenly referred to as the ‘DB-9’ connector,” says NullModem.com. However, since I’ve always heard it called a DB9, that’s what I’m going with.)

For the PC1ASL project, here are the pin numbers and connections I think is correct:

  1. not used (it would be for right-channel audio but I am only using the left-channel)

  2. Audio out (left channel) to 5KΩ potentiometer center

  3. COS to microphone jack PTT pin 2

  4. not used

  5. not used

  6. Audio input from MAX9814 audio amplifier (level controlled by 5KΩ potentiometer)

  7. not used

  8. Ground

  9. not used

4.2.2 Microphone jack

For the microphone jack wiring, I pulled information from the great allscan.info instructions for building your own AllStarLink node.

8-pin microphone jack

Pin number and connection:

  1. Microphone audio through a 5KΩ potentiometer to MAX9814 to RL-20 DB9 pin 6

  2. PTT to RL-20 DB9 pin 3

  3. not used

  4. not used

  5. +5VDC in from the RL-20 MIC +5VDC pad

  6. not used

  7. Microphone ground to RL-20 DB9 pin 8

  8. Ground to RL-20 DB9 pin 8

4.2.3 Audio amplifiers

PAM3806 audio amplifier board

The PAM3806 audio amplifier is used for volume out to a mono earphone/headphone or external speaker.

  • Audio from RL-20 DB9 pin 2 is fed to the PAM3806 amplifier.

  • Audio from the PAM3806 (left channel only) goes through a 5K potentiometer to a 1/8” TRS stereo jack on the back of the PC-1A case.

Tom Salzer

Tom is an Extra Class amateur radio operator licensed in the United States as KJ7T

Tom Salzer KJ7T