The Nouveau Riche of Ham Radio: Are Digital Modes Today’s CW? (And A Look At The Venus DR-4020 Digital Transceiver)

It was one of my buddies who really put a bug in my ear about the use of RF digimodes in a city landscape. He’s been itching to build the QRP Labs QDX Digital Transceiver.

I did not instantly see the excitement. FT8 is a fun mode at times. I have enjoyed JS8 call. WSPR is fantastic. But when operating portable–my personal ham radio niche–it means a computer needs to go with you into the field, and I do not particularly dig that.

But then some friends showed me an extremely cheap PC that Microcenter (an electronics and computer store) was selling, the Evolve III Maestro. For $60!!! O_o (that is an old-school “confused” emoticon by the way. Why would any store sell a fully functional small PC for so cheap?)

Now, combine this with a pre-built digimodes transceiver I just happened to come across by reading Donald KL7KN’s QRZ profile page. A Venus DR-4020. I bought it and less than 3 business days later, it was ready for pick up at the local DHL customer service facility. (As always, I am absolutely not sponsored by any company anywhere. I am just telling you about my stuff…)

The transceiver is simple with a power button on the left. A transmit (TX) red led above it. And a memory scroller, VFO, and band changing knob on the right.

The backside simply has “DATA” “IN” and “OUT” ports. These really are only audio jacks with speaker “OUT” and microphone “IN” for 3.5mm TRS stereo/audio cables. There is an antenna port with a female BNC connector. And a power cable jack labeled 10-14V.

Included with the radio were 2 male-to-male 3.5mm TRS cables, an speaker/mic audio-to-USB converter, a male BNC to female SO-239 adapter, and a power cable with one barrel connector for the radio and unterminated distal ends. I terminated the power cable with Anderson Powerpoles as I usually do. (How to do it: HERE.)

While it was nice of the company to include these peripherals, they are all junk. The BNC-to-SO239 adapter makes poor connections. The audio-to-USB interface does not seem to work. And one of the audio cables is flat out broken. The company should save its money and just make some recommendations to the user. Given that the Evolve III Maestro PC only has a single audio out headphone jack, I decided to get a Creative Labs SoundBlaster G3 External USB Digital-To-Analog Converter (DAC) and Amplifier soundcard.

The power cable is useful however, and you can see how I added Powerpoles, along with a little extra heat shrink tubing that I am particularly fond of.

Setup is straightforward. Attach the radio to the 3Ah Bioenno LiFePo battery.

Connect the Sound Blaster to the USB port of the PC. Check the devices to make sure it is recognized; it should not need any additional drivers. I have found that it is necessary to make sure the Sound Blaster is plugged into the computer first without any of the TRS cables plugged into it.

Now hook the “OUT” jack of the DR-4020 to the microphone jack of the Sound Blaster using one TRS cable. Hook the “IN” jack of the transceiver to the headphone jack of the Sound Blaster with the other TRS cable. Turn the Sound Blaster microphone and speaker volumes up all of the way. Switch the microphone setting on the Sound Blaster to on, and the “Mixing”/”Vol” switch to “Vol”. The volume should be all the way up. Make sure the front center button, i.e., the “footstep enhancer” for you gamers out there, is not illuminated on.

Open up WSJT-X and open the “Settings” dialogue box. Under the radio tab, choose “None”. Under the PTT method, choose “VOX”. VOX, or “Voice Operated Exchange” is a setting whereby the transceiver will transmit upon hearing a sound over a certain threshold loudness. The Venus DR-4020 operates under VOX mode at its baseline. Essentially, when WSJT-X sends its whiny audio signal out into the Sound Blaster speaker cable and in to the DR-4020, the transceiver will begin to transmit.

Switch to the Audio tab. Choose “Microphone (Sound Blaster G3)” as the Input. WSJT-X will then listen to any signals coming back into the Sound Blaster from the audio output jack of the DR-4020 receiver. Choose “Speakers (Sound Blaster G3)” as the Output. This will force WSJT-X to send its audio signal out into the Sound Blaster, and initiate transmission by the DR-4020 by VOX as described.

That’s it! Either press the VFO button to change between 40M and 20M, or turn the dial to get to the appropriate channel. Keep in mind there is no CAT control, so you have to tune the VFO manually. Change the other settings as desired and WSJT-X, including FT8, FT4, WSPR among other digimodes, is ready to go! FlDigi and JS8Call use very similar set up parameters.

As you can see below, I am able to make contacts at my qth with this set up on FT8. I used my home antenna, a 40M OCF on a 6 foot privacy fence in an alleyway, in the heart of South Boston. Nominally, the Venus DR-4020 puts out 4W, though I did not actually test it yet. WSPR worked equally well. I could transmit on RTTY using FLDigi too.

Bottom line for me is that I am so far quite pleased with the Venus DR-4020 digital transceiver. I was happy enough not to have to build it, although the QRP Labs QDX Digital Transceiver has more functionality including more bands. And it is half the cost at $69. Most likely I will end up giving the QDX a try too.

The following table gives a breakdown of all of the components necessary to get the Venus DR-4020 on the air, at least on 20M. I was in possession already of all of the items except for the transceiver (obviously) and the Sound Blaster G3.

This chart also shows the breakdown of weights, coming in at 5 1/4 pounds for the entire kit. By comparison, the Yaesu FT-891 transceiver by itself is 4.18 pounds. Whereas the Elecraft KX2 is 13 ounces, and its “Shack-In-The-Box” option, which really only covers the transceiver and desirable add-ons like a clock and autotuner, is $1472.60. Both the FT-891 and KX2 require some sort of digital interface / external soundcard, unlike the Icom IC-705 that is plug-and-play with its computer interface. The IC-705 is currently selling for $1349.95 and weighs 2.4 pounds with its internal battery in place.

So, who exactly is this very limited functioning transceiver for? Circle back to the beginning where I said that I was not too excited by the prospect of a digital-only radio build. Well, I am starting to have a change of heart.

High up on my list of ham radio jealousies is the fact that CW operators have a host of small, lightweight, efficient transceivers to bring with the onto summits. As any reader of this blog will quickly realize, portable operating, and in particular Summits-On-The-Air (SOTA), is my RF niche. I am not a particularly proficient CW operator, despite giving it a fairly concerted effort. And therefore I am largely shut out of operating small, low wattage rigs. I know, SSB contacts are obviously possible with qrp rigs, but, let’s just say that has never been my preferred style. I want 100 watts for SSB and typically summit with my FT-891. My full portable radio kit, complete with a 15Ah LiFePo battery, is approximately 15 pounds in weight.

Now lets talk qsos. For SOTA, 3.6 million contacts have been made by CW. Not far behind, SSB has been the mode of choice for 3 million qsos. Digimodes only account for about 43,000 contacts by comparison. The obvious reason for this in my opinion is who the heck wants to drag a computer up a mountain? And the fact that the SOTA program predated FT8 (which was introduced in 2017) by about 15 years, I imagine also plays a role in this statistical skewing of the modes used on summits.

Enter now the age of the SDR, shrinking technology, and now a diminutive $60 throwaway laptop. A 5 1/4 pound complete radio kit that can send text messages all over the world is now becoming extraordinarily attractive to me. I do not need to learn to head copy CW in order to participate in the phenomenon of small, efficient, qrp rigs. (Though don’t get me wrong, I would still like to become a proficient CW operator).

So, I am left wondering now. Are digimodes the actual successor of CW? For an impatient society who may not see the value in committing series of beeps and boops to memory, will the ability to send and receive text messages free from corporate infrastructure be the impetus for Morse code’s modern day replacement? My temptation for playing radio with a small form factor that can truly facilitate efficient communication is starting to climb. And it is kinda nice to know it doesn’t have to be a CW rig after all. So, who are these small digimode rigs for? It looks like, quite possibly, me!

As always,

KM1NDY