Radio – Geronimo/370

Last connections made (QSO’s)

Posted on2022-05-262023-04-04

Below you can see the last 15 QSO’s I made, as logged on QRZ.com. A yellow star means the contact has been confirmed by the other station, a little grey circle means confirmation has been requested. Normally I ask for confirmation with each contact; absence of a yellow star or… Read the rest

Common mode filters

Posted on2022-05-212022-05-214 Comments

This afternoon, I will be taking my Novice exam. So in preparation of being allowed to transmit, I decided to create a barrier for HF. I did so by making a number of loops (7) in the coax cables, just above the ceiling. These loops act as coils and they… Read the rest

FT8 data from the noise

Posted on2022-04-302022-04-30

It’s truly amazing what can be accomplished with digital modes like FT8… Noise Have a look at this waterfall, it looks like the 10 meter band is dead, it only shows a few very faint signals in the 10 meter band: Despite the weak signals, the FT8 program I use,… Read the rest

NanoVNA measuring antennas

Posted on2022-04-222022-04-23

Yesterday I received my NanoVNA (small Vector Network Analyzer). Among other things we can measure the return loss in antennas (or the Voltage Standing Wave Ratio or VSWR for short). Return loss or VSWR VSWR is the ratio between the energy that goes to into the transmission line TO the… Read the rest

Coax switches, measuring

Posted on2022-04-172022-04-17

An interesting video by W2AEW about measuring on coax switches to make sure one can leave a receiver connected when transmitting over another connection of the same switch:… Read the rest

SDR control iPad app for ICOM sets

Posted on2022-04-162022-04-16

Today I came across a very nice app with which one can control Icom transceivers. It is available in the App Store and it’s called SDR-Control for Icom. It works for LAN connected radio’s, so no cables needed, you can operate your set via Wifi. Icom’s IC-705, IC-7610 and IC-9700… Read the rest

Switches connected

Posted on2022-03-182022-03-18

I have made a little diagram showing how my antenna’s and rigs are connected. So I can switch my 2mtr/70cm antenna to three sets, and the HyEndFed for 10,20 and 40 mtr to two sets. Numbers in the arrows indicate switch settings. See below: Antennas, switches and sets… Read the rest

Antenna switches

Posted on2022-03-052022-03-054 Comments

Yesterday I ordered some antenna switches (from HAMshop, where else?) and today they came in. One is for HF and the other for VHF/UHF and higher. See pictures below. Also, I have a question for fellow HAM’s, please have a look at the bottom of this post. HF switch (PL… Read the rest

Origin of radio numeric codes

Posted on2021-12-272021-12-27

Searching for the origin of the ‘73’ code at the end of a message, meaning something like ‘kind regards’, I found the following. Glen Zook, K9STH, posted this to the Heathkit mailing list: Many amateurs already know that “73” is from what is known as the “Phillips Code”, a series… Read the rest

Christmas in the shack

Posted on2021-12-272021-12-27

Do you guys also get the Christmas feeling and make it visible in your shack / workshop? What do you think, is an image like this recognizable? I do… Xmas shack… Read the rest

Resonance measurements / filters

Posted on2021-12-052022-03-02

Yesterday I started with Capacitors / capacity and coils / inductance. Today I did some extensive measuring, first on a C and L in a series tuned circuit, then on a parallel tuned circuit. See schematics here below: For these measurements I used the same setup as yesterday. But this… Read the rest

Resonance frequencies

Posted on2021-12-042021-12-041 Comment

In the HAM course I am following to become a licensed radio amateur, the topic of resonance frequencies came along. To wrap my head around it I did some experimenting. You can find the result below. I have an assortment of capacitors and coils that I can use for these… Read the rest

HAM-gadget (6) – adjustment & enclosure

Posted on2021-11-132021-11-13

In this version I built in the possibility to adjust the summer and wintertime offset from UTC. It’s a very crude offset, I just add or subtract the offset from the UTC hour. Have to think of a better way to do this… Enclosure I built in the gadget in… Read the rest

HAM-gadget (5) – menu structure

Posted on2021-11-072021-11-08

This weekend I built in a menu structure into the HAM-gadget. Also I created a possibility to store and retrieve settings to the ATMEGA328P’s EEPROM, so they are saved for the next time you switch on the device. For now, you have to retrieve them manually, but that’s quicker then… Read the rest

HAM-gadget (4) – keyboard added

Posted on2021-11-052021-11-06

After a lot of fiddling, trial and errors, I finally got the matrix keyboard to work. Also, as the project has passed the prototype stage, I threw together everything on a PCB in preparation for mounting it in a casing. Note to self:next time first cut the PCB to size… Read the rest