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Dell G3 3779 17″ with Ubuntu 18.04 LTS

Posted on by AE0BQ

Recently got a refurb Dell G3 3779 17″ with i7-8750H 6 core, Nvidia GTX 1050 Ti GPU, and 32GB RAM. Perf is awesome, passmark is over 12000. Running Ubuntu 18.04.2 but had trouble with jerky performance and stability issues, until I found this page:


  • install Ubuntu 18.04.2 from .iso
  • sudo apt update && sudo apt upgrade
  • sudo nano /etc/default/grub.d/Linux-Dell-Video.cfg:
    GRUB_CMDLINE_LINUX=$(echo $GRUB_CMDLINE_LINUX acpi_osi=Linux-Dell-Video)
  • sudo nano /etc/default/grub.d/Nvidia-DRM.cfg
    GRUB_CMDLINE_LINUX=$(echo $GRUB_CMDLINE_LINUX nvidia-drm.modeset=1)
  • sudo update-grub
  • sudo apt install r8168-dkms
  • sudo apt install nvidia-430
  • sudo dpkg -i tlp-sensible_1.1_all.deb
  • sudo dpkg -i modprobe-blacklist-psmouse_2_all.deb
  • apt install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04
  • sudo reboot now

OMAP Blaze

Posted on by AE0BQ

I picked up three of these Blaze handheld development platforms at the recent hamfest, for about $3 each.

Texas Instruments created these back in 2010, to streamline application software development on their OMAP 4430 ARM Cortex A9-based system on a chip (SoC). The OMAP 4430 SoC was also used in the Pandaboard.

Blaze technical docs and firmware:

OMAP 4430 SoC



  • dual 3.7″ capacitive WVGA touchscreens
  • 3 multi-megapixel cameras
  • DLP pico projector
  • HDMI out
  • accelerometer
  • compass
  • light sensors
  • temperature sensor
  • barometric pressure sensor
  • proximity sensor
  • Wi-Fi
  • GPS
  • Bluetooth
  • FM receiver
  • microphone input
  • stereo speaker output
  • PCIe slot for 3G modem

License anniversary

Posted on by AE0BQ

My FCC Amateur Radio license was issued April 11, 2018. It’s been a good year.

I enjoy participating in my club’s regular activities, such as the Thursday night net, Saturday morning breakfast, and monthly meetings, as well as various special events, such as field day, monitoring local events, etc. I also enjoy being a VE – feels good to give something back to the community and the hobby.

samlex SEC-1235M

Posted on by AE0BQ

Picked up one of these at a recent hamfest. Didn’t have to pay shipping or sales tax, so I call that a bargain. Needed a slightly bigger PSU than the MFJ-4225MV, but still use that for chatting on local repeaters with the 25W QYT-8900D.

HF digital modes on IC-7300

Posted on by AE0BQ

As it turns out, you can connect a USB cable from a PC to an IC-7300, and run some free software, and instantly enjoy a bunch of HF digital modes. The IC-7300 appears to the PC as two separate USB devices – an audio interface, and the remote CI-V (CAT) serial interface, so no additional hardware is required. Pretty sweet!

So the two softwares are fldigi and WSJT-X.

WSJT-X software handles FT8, JT4, JT9, JT65, QRA64, ISCAT, MSK144, and WSPR, and Echo.

But, I haven’t tried out WSJT-X yet. I’m struggling to understand fldigi. Also there may be some IC-7300 settings that aren’t optimal as well. I can see the audio on the waterfall and oscilloscope displays, and the frequency and radio knob are synced, so both the USB interfaces are working and fldigi is configured correctly. I think the RX levels might not be optimal, because it decodes garbage. PTT works (radio transmits), but I don’t want to transmit until I know receive is working correctly and I have a better understanding of everything.

This link may help me understand the basics of fldigi:

DIY halo antennas for 2m SSB

Posted on by AE0BQ

A halo antenna is a horizontally polarized, omnidirectional, ​1⁄2 wave dipole, bent into a loop with a small break on the side of the loop directly opposite the feed point.

2m FM uses vertical polarization by convention, whereas 2m SSB uses horizontal. Using the wrong polarization results in about 20dB loss.

A stacked halo configuration uses two identical antennae oriented one above the other, fed in parallel through a phasing harness. The stack adds gain in the horizontal plane with a corresponding reduction in the vertical plane. The realizable gain is around 8dBi.

A directional antenna such as a Yagi can provide a little more gain (9+ dB), but requires an antenna rotator.

The halo antenna characteristics — omnidirectionality and horizontal polarization — make it a good choice for 2m SSB.

Mike Fedler, N6TWW, has documented several of his halo builds. His web pages and videos are extremely detailed, and capture the entire process including dimensional calculations, materials, fabrication, assembly, and tuning.

Single halo made from soft copper tubing and PVC pipe.
Stacked halo.
Stacked halo made entirely from aluminum bar, rod, and tube stock…. 15 videos, amazing level of detail here!
Videos about DIY halo antennae.

SSB on 2m using a 10m SSB radio with a transverter

Posted on by AE0BQ

Everybody knows that 2m FM is how we talk to our ham radio buddies on the local repeaters. Just pick up a janky Baofeng HT for $25, plug in the repeater settings, and you’re good to go.

But SSB is much more efficient than FM, and when conditions are right, SSB contacts can be made with stations over a thousand miles away!

Of course, this requires a radio that can do SSB on 2m. If you are lucky enough to have an expensive all-band all-mode radio that can do SSB on 2m, then you are all set, and you can stop reading this right now. Most of us have 2m transceivers that can only do FM.

But….if you have an HF radio or QRP rig that can do SSB on 10m, then you can do SSB on 2m by using a transverter.

What is a transverter? It’s a circuit that sits between your 10m radio and a VHF antenna, and bidirectionally converts between the two frequencies — 28MHz and 144MHz. The HF radio outputs SSB at reduced power, and the transverter converts that up to 144MHz and drives your VHF antenna. Similarly, the transverter receives on 144MHz and converts it back down for your receiver. The transverter has an internal RX/TX relay that is controlled by the PTT output of the HF radio.

This arrangement will work for any modulation that your HF radio or QRP rig is capable of. My ICOM IC-7300 supports CW, SSB, LSB, AM, and FM, and can also handle a variety of weak signal digital modes using fldigi and WSJT-X software. Most multi-band HF radios have similar capabilities. The µBITX is a low-cost QRP kit that will do SSB on 10m.

The input of the transverter handles 28-32MHZ, and the 10m band is 28.0 through 29.7 MHz, which means you can cover 144.0 MHz through 145.7 MHz in the 2m band. Lots to experiment with here!

I ordered the following transverter kit for $75, which includes shipping from Ukraine. Output power is 10-15 W with an input of 50mW, so the kit includes an attenuator board. The boards are fully assembled, tested, and tuned. The kit includes everything shown in the picture.

(Pic says 70MHz; I ordered 144MHz.)

Transverter Board Specifications
RF range – 144 … 148 MHz
IF range – 28 … 32 MHz
IF input power – 1 … 50 mW (0.05 W max.) or 0 … 17 dBm
LO frequency – 116 MHz (3rd overtone of 38.6666 MHz crystal)
LO frequency stability – +/- 3 ppm
Output power – 10 … 15 W
RX gain – typ. 20 dB
Noise figure – typ. 1.0 dB
Image rejection – typ. 70 dB
PTT control – Contact closure to ground
Supply voltage – +13.8 V DC (+12 … 14 V DC)
Current consumption – typ. 2 A (TX)
TX Output transistor – RD15HVF1
RX Input transistor – BF998
Dimensions (mm) – 80 x 45

Attenuator Board Specifications
Attenuation Level – 30 dB (10 W IN – 0.015 W OUT adjustable almost to ZERO)
RF Input Power – 5 … 10 W (15 W Maximum)
HF Bypass Power – 100 W
PTT control – Contact closure to ground
Supply voltage – +13.8 VDC (+12 … 14 VDC)
Dimensions (mm) – 39 x 67

Following are some links about 2m SSB.

FCC issues warning about non-compliant (BaoFeng, etc) radios

Posted on by AE0BQ

FCC DA-18-980A1

Simple summary from a simpleton (me), who is also not a lawyer. YMMV and I could be wrong. More words = more confusion.

1. It is illegal to market/distribute/sell radios in the US that tx outside US ham bands, without having the appropriate certification (e.g Part 90, etc).
2. Some Baofeng and derivative/similar radios allow tx outside US ham bands, and this ability can be reconfigured in the field.
3. It is perfectly legal for US Amateur Radio licensees to possess and use such devices, as long as they do NOT tx outside US ham bands.
4. Baofeng and the other OEMs can easily remedy this situation by changing their firmware to disallow configuration.
5. Field modification of hardware to “open up” tx on all freqs is a completely separate issue.

I don’t know or care about commercial, air band, etc, but as for hams, it seems you are free to continue using your BaoFengs…or any device, whether commercially manufactured, hacked, or home brew….as long as you don’t tx outside ham bands, or outside your license class band and mode restrictions.