I/O: Stuff on the Bench

Bringing some more older tech into the shack

Photo of old radios for interest. Photo by Skitterphoto: https://www.pexels.com/photo/radio-transmitter-lot-9295/

Kenwood TM-D710

I picked up a Kenwood TM-D710 radio recently. It came with a GPS unit that unfortunately takes a long, long time to actually find and lock onto satellites. I was hoping the package would work out of the box to display APRS waypoints while I drove but alas, this was not the case.

The TM-D710 is the model before the TM-D710G. I assume the “G” stands for GPS because the earlier model does not have a built-in GPS receiver, hence the need for an external device.

I have a couple of backup plans for this radio. One is to use an older Garmin Nuvi 350 as the external GPS. I’m waiting on a cable from Argent Data to interface the radio with the Nuvi.

The other potential use I see for it as as a local digipeater/igate at home.

Garmin Nuvi 350

I have one that is not working well. Fortunately, these older units are dirt cheap on eBay, so I ordered up a couple more packages. Between the three packages of Nuvi’s, I’m sure I’ll be able to end up with at least one, and maybe two, working systems.

Kenwood TH-D74A

I would love to acquire one of the shiny new Kenwood TH-D75 radios, but what I see in the forums is the price is likely to be north of $800. For a handie talkie. Ouch.

Instead, I picked up a used (but in excellent physical condition) Kenwood TH-D74A for about $500. It’s charging in the cradle now and I’ll configure it later today.

Hopefully, using D-STAR on this radio won’t be too cumbersome. I want the APRS service it provides. I want the tri-band transmission capability (70cm, 1.25cm, and 2m). And I want/hope that the battery is in good shape because replacements are a bit pricey!

Edit: After charging and setting it up, APRS is working!

Screenshot of KJ7T-7 beacon, plotted on map

Apple iPhone 7 Plus

Wait a minute! What is an iPhone doing in my amateur radio blog? I intend to use it in two ways: (1) as a softphone for one of my VoIP lines, and (2) with the RepeaterPhone app for AllStar-In-the-Pocket (I’ll call this “AIP”) capability…as long as I have wifi coverage.

I’ll probably pick up another Google Fi data SIM card and see if it will work in the iPhone. That would give me 4G cellular coverage within the T-Mobile footprint and thus extend my AIP range. With a car cradle, I can also enjoy some of my favorite AllStar nets while I’m on the road.

The iPhone is purported to be in excellent condition and comes with a 1-year warranty. I purchased the 256 Gb model so it can also be used to store and carry some additional data and documents.

Older Kenwood radios

I have an old Kenwood TS-520S. I bought it in good but “well loved” condition from W7FBI (SK) and it still has his pencil marks on the Drive dial. I enjoyed this radio very much during the earliest part of my amateur radio journey. Later, I replaced it with a solid state Yaesu FT-450D that has been my workhorse radio for years.

Why might I be lusting for another old Kenwood radio? Two reasons. First, the models with a general coverage receiver boast strong reception. Second, the audio quality is, to me, very pleasant, especially compared to other radios I’ve been around.

I’m eyeballing some old 6-meter rigs and Kenwood TS-690S rigs. I’ve also been poking around at Kenwood TS-670 radios. No decisions have been made.

Other old radios

I’ve got the old Heathkit Mohican receiver to go through. I’m sure it will need to be re-capped.

And the old Zenith shortwave with Wave-Magnet hasn’t been powered up yet. That rig will undoubtedly need some cleaning, if not more.

In the truck

When my Kenwood TM-D710G starting acting up, I pulled my backup out of the cabinet. That backup radio is the Icom ID-5100A. It’s been a convenient radio for a daily driver, even if it doesn’t have the Kenwood feel to it. I confess that I’m more comfortable with the Kenwood design language.

Yaesu used to make a four-band mobile radio, the FT-8900R. I always wanted one of these units, even though I can’t see doing much on 10 meters via repeater or FM simplex.

That radio is no longer manufactured. The closest analogue is the TYT TH-9800 quad band radio with cross-banding capability. At around $200, it’s pretty cheap…and it may, in fact, be cheaply made, but it feels like it would be worth giving it a go. I do want to have 6 meters in the vehicle so this would be a way to achieve that.

Deep enough. I’ve also got LoRa devices on my mind and POCSAG/DAPNET pagers, but that is fodder for another post down the log.

Best wishes to all for a happy, healthy holiday season!