Amateur Radio IC-705

Satellite Memory File for IC-705

This is a memory group file over satellite frequencies for Icom IC-705 and CS-705 software. It is not complete and will be updated. Feel free to use it, change and add.

The memories for FM transponders are used like this:

  • Channels named with satellite name, for exemple ”PO-101”, are used in split mode. This channel can be used when using the IC-705 for portable operation or without an extra receiver .
  • Channels named with satellite name and Uplink, for exemple ”PO-101 Uplink”, are used only for uplink (not split). This can be used with software like SDR-Console v3 (external radio) or if you have an extra receiver.

Import the memory file into CS-705:
Note! Be sure that you not overwrite anything in your IC-705 when cloning. Make a backup of your current settings!

  • Create a new memory group
  • Mark this new group
  • Choose File->Import->Group and choose the .csv file
  • The memories will now be imported to CS-705
  • Clone to your IC-705.

IC-705_SatFrqMemGroup.csv (Downloaded from AMSAT-SM website)

Amateur Radio IC-705

First satellite QSO since 1993

Today, 2020-11-11, I made my first satellite QSO since 1993 (when Oscar-13 was alive). My two QSOs was via PO-101, IC-705, 10 watts output to 13 el X-Yagi.


IC-705 vs RS-918 with FT8

I was interested to know how my RS-918 (a mcHF SDR HF radio clone) performed with FT8 compared to my new IC-705.
I have done a series of test. Very non-technical tests, without any promise if this is the truth. But it was possible to repeat the results several times. I have done the following:

  • RX test: 10 minutes with one radio, switch antenna and then 10 minutes with the other radio. Then counting number of received stations.
  • TX test: 10 minutes with one radio, switch antenna and then 10 minutes with the other radio. Then counting number of stations that could RX my signals.
  • Test done on 20 meter (14 MHz) and 40 meter (7 MHz) band during day and evening time.
  • 5 watts output was used. The RS-918 needed a little PA calibration to reach 5 watt.
  • The tests has been repeated three times on both TX and RX.

What I can see is that the number of station received are similar, in the image below the RS-918 actually received more stations but in the other tests I could not say that one of the radio was better than the other.

IC-705 RX 40 meter
RS-918 RX 40 meter

In all tests, the IC-705 performed better. The output (5 watts) is the same but it seems that the IC-705 have some more punch in the modulation. I do not know, I have not investigated this further…

So, for some ”local” FT8 contacts in Europe I can use the RS-918 but if I would like to hunt some DX I will use the IC-705 with 10 watts.

IC-705 TX 40 meter
RS-918 TX 40 meter

IC-705 doppler correction with SDR-Console

Here a short video of IC-705 Frequency and Doppler control from SDR-Console.
The first part is frequency control with VFO following the radio.
The second part is doppler control from the Satellite External Radio control.

Download the OmniRig config file from: https://sm7iun.se/station/ic705/
Be sure to use the correct CI-V hex code in the seetings for IC-705.


IC-705 doppler correction with PST Rotator

To setup the new IC-705 for doppler control with PstRotator software you just have to follow these steps:

  • Download the OmniRig file for IC-705 from here https://sm7iun.se/station/ic705/
  • Be sure to set up the IC-705 for USB control according to the manual from Icom
  • Follow the guidelines in PstRotator documents for satellite and rig control, choosing IC-705 from OmniRig setup

Here a short video after the setup:

Amateur Radio

First HF portable test

First portable test at my garden. FT4 on 20m. RS-918 5 watt to an end fed half wave antenna. Very good result, easy to make QSOs.

Amateur Radio

Trapped End Fed Half Wave (EFHW) for 15/20/30 meter

Inspired by this excellent article from PeanutPower I decided to build a resonant End Fed Half Wave (EFHW) antenna for portable use. My antenna is designed to be resonant on the digital sections of 15, 20 and 30 meter ham radio bands.

All measurements done with NanoVNA.
You can click on all images below to get a large image.


The 1:64 UNUN is made just like this post that I have published before, with the 100 pF capacitor added later for better 15m SWR. You can see that the SWR is higher on high frequency but it was possible to get a good SWR on 15m, when antenna wire was added.
BNC connector are used because that is my standard for HF and portable connectors.

UNUN without 100pF
UNUN with 100 pF
UNUN with 100 pF
Test measurement of UNUN with a 5k ohm resistor

Sotabeams QRP Pico Traps

Traps used are Sotabeams Pico Traps. It took me a two hours to build, unfortunately I lost the small SMD 100pF capacitor so I used bigger ones. I also need to unwind one turn for each inductor to get in resonant.

14 MHz trap
21 MHz trap

Setting up the antenna (wire) sections

This was the most time consuming part. First I used an online antenna calculator to get the sections length. These are the calculated length but I added aprox 50 cm to each before mounting:

Frq (MHz)Sections (m)
21,1 MHz6,68 m
14,1 MHz3,4 m
10,1 MHz3,9 m

Begin with the highest frequency (band). Get the antenna up – measure – down – cut wire – up – measure – down – cut wire…. until you have good SWR for all three bands.
Wire used are from Sotabeams.

This is the result. As you can see very good on 20m and 30m.
On 15m SWR is 1.68:1 – OK but not perfect.
Note: after adding a 100pF capacitor at the input on the UNUN the SWR on 15m got flatter and lower.

Antenna SWR for all three bands

This is how the antenna can be used:

And everything ready to go!