Hermes Lite 2 Questions and Answers


Q. What is a Hermes Lite 2?
A. It is an Software Defined Radio transceiver. It is the hardware part of complete radio. The other part is your computer and the software that you choose.

Q. Do I need a big powerful computer?
A. No. I have used a Paspberry Pi 4B and a program called "Quisk" and it worked just fine! BUT the nicer programs with all of the nice features, like better filters and nicer audio and lower latency and prettier screens, require a bigger faster computer!

Q. How much do I need to spend.
A. The HL2 will cost nearly $380 USD, and that's for the radio circuit board, the filter board, the case and the shipping.

Q. How much for the software?
A. It's free! Some programs will ask for donations (which is only fair if you choose to use it), but none require a purchase. That is mighty darn nice of those who wrote the program, because they have spent hours and hours writing it and then giving it to you.

Q. So how's the receiver? Is it as good as the Anan?
A. It's darn good! It's performance is closely tied to the computer's performance. That's where it's all done, the filtering and recovery of the signal. It's also necessary to consider how you will be using it. Ragchewing on 7163, you will not see any difference ...none. If you intend to attach a converter for use on VHF and UHF or chase DX or contest, you will likely see a difference.

Q. Is it as complicated as it sounds?
A. Yes! Remember, it's cheap! It's not a product, but a project. If you know which end of a screwdriver to hold AND know your way around a computer, you're all set. If you don't understand how to create a folder and move files into it, you will be wasting your time and money, and be very pissed off! Since the computer provides the audio for the HL2, you will need to understand how to connect your microphone and speakers also.

Q. Isn't there any support?
A. It is supported by the Hermes Lite Community, Steve kf7o the project leader via the Forum, an online Forum itself, and by your friends. I will say this again, it is a project! Support facilities and people cost $$$, big $$$. You will be purchasing the HL2 from an electronics assembly factory that makes many other products and they will run a reasonable test of the completed board. They do not offer support, they likely don't know what it is! Again, it is a project!

Q. You say reasonable test. Can I get a bad one?
A. Yes. The failure rate is around 3%. That means that for every 100 that they make and test, about 3 will arrive and fail. The project creator Steve KF7O has been helping fix bad boards but remember he's not getting paid anything to do this!

Q. What about availability?
A. Here are 3 links for you.

If you have any specific questions that I can help with, please email me at the email address that is listed on QRZ.COM.


My Hermes Lite 2 That I Have On the Air




On February 16 2023 I placed an order with Makerfabs of Shenzhen China for a small HF SDR transceiver called the Hermes Lite 2. Note that this is Build #10. There are 3 pieces, the transceiver, the filter board and the case. I received package from DHL on 3-13-2023. That was one day before the DHL tracking predicted.

It is extremely clever! It uses a modem chip that normally is used in cable TV modems, made in huge quantites and is inexpensive. It can run with several pieces of software, on both Linux and Windows, and will run with Thetis.

The transceiver was assembled in less than two hours. That's only half of it however. There's the software setup and configuration on the computer to contend with. My transceiver worked perfectly on power up!




Download and Tested Software

SDR Console

Perhaps the simplest and easiest to install and get running is Simon Brown's SDR Console. Simply download it from the link below and install it, according to instructions in the Quick Setup Guide.

Thetis

After some detective work I've found the latest versions of Thetis and the Hermes Lite 2 modification code as of 3-10-2023. Here are the links. I've downloaded and use the x64 versions of each.


The software setup is very straightforward. You simply install Thetis 2.9.0.6 from the Github link above. It creates the necessary folders for you. Then you download the 2.9.0.6 b2 files from Github. Unzip the files and move them into a folder of your choice. I renamed the folder to ThetisHL2 and moved it to c:\Program Files\OpenHPSDR\. I made a desktop shortcut to the Thetis.exe file, in that folder, to start the program.



Inside the Tyvek Package



The delivery will be via DHL. My first Hermes took 7 days and this one appears to be on the same schedule. 7 days from Shenzhen isn't bad! Here's what I received.


After unpaking and looking everything over, I attached the rear plate to the bottom part of the case. I removed the HL2 board and slid it in the proper slot in the case, from the front and attached the front plate with the bottom 2 screws. Sliding the main board forward, and making all of the front jacks and holes match up, I could easily see where the heatsink hole should be located. I used a 1/8 inch bit, which fits the hole perfectly, with the sharp end down and twisted it to mark the spot where the heat sink hole is to be drilled. 


Removing the front panel and board, I used a center punch and lightly tapped it to create a perfect spot for the drill to begin. I might add that you do not want to hit the center punch very hard. You do not want to dimple or distort the area of the case that will need to contact the heat transfer piece. For the same reason do NOT use a Dremel or other power tool for the job. You need to remove paint not metal and a power tool will be much too aggresive.








After removing the front panel and board I began removing the paint from the area where the heat transfer piece will sit. This area must be very smooth, mirror like, to be most effective. I began with 320 grit sandpaper, checking often by positioning the heat transfer piece to be sure that I was removing paint from a sufficient area. Next I cut a piece of 1000 grit sandpaper to polish the area where the paint was removed. I found that by cutting a strip of sandpaper, as wide at the heat transfer piece and using a pencil eraser to push it back and forth, this was a much easier job than I thought it would be!


Before drilling, I reinserted the board back into the case and reattached the front panel to verify that the center punch mark was exactly where I wanted it.













Next, I turned my attention to the heat transfer piece. All metal surfaces should be as polished as possible to maximize the metal to metal contact area. Yes, I will use heat sink compound but just a very thin coat will be needed. Here are the heat sink surfaces that I also polished with 1000 grit sandpaper. Notice the difference from the picture above, before the surfaces were treated.


Using a new 1/8 bit, I carefully drilled the heat sink hole. I purchased 3x12mm black hardware and it's the perfect fit. Note also that the case is supplied with screws to attach the front and rear panels. Unfortunately they are flat head screws and tightening them will cause the front panel to warp. The front and rear panels are both quite thin and distort easily. The screws are also the 3 mm size and picking up some pan head screws are recommended. My local Menards had a good selection of black metric hardware!












After putting a light coat of Arctic Silver heat sink compound on the mating pieces, I slid the board and heat sink hardware into place and fastened it down. It appears to work quite well. Using a laser thermometer and the inbuilt heat sensor I can verify that the case stays in the range between 30 deg C and 40 deg C during SSB QSO's. I have not tried FT8 with the HL2. The case, to the touch, feels luke warm and even after long transmissions, it never gets close to hot or even warm.



Next, I installed the rear panel, the heatsinks and the connector that connects the harmonic filter and the HL2 motherboard.















I first brought up Thetis. It appears that you must have a microphone plugged into the computer or VAC recognizes what it called an "empty channel"!



Later I heard Jack testing and recorded him and shot him the email. He came back calling me on the air. I had no way to transmit, I thought, but picked up the headset and hit transmit. He heard me!!! 3 watts PEP and nearly 200 miles on 80 meters in the daytime!

















I have used Thetis for a couple of years now and because of that, I find it like an old pair of slippers, quite familiar and comfortable. I haven't the time behind the other software yet to be fair. Right now Thetis is my pick!



This morning I used SDR Console on 3660khz. It was different to setup and use than Thetis but easily done. I think the graphics are more mature and extremely flexible and the audio, both transmit and receive is, noticeably better.



I've also used LinHPSDR on Linux Mint 20.2 on the air. It loaded and configured as the instructions say. It was a pleasure to use and quite different than Thetis or SDR Console but it worked well.



--- Larry W8ER ---