F4EGM – Radio Amateur Station

Mostly active in mobile.

Previously licensed as F0EGM.

Transceivers

  • YAESU FT-991 – Base station (QTH)

  • TYT UV390 GPS – DMR + APRS handheld (stock antenna)

  • TYT MD-9600 OpenGD77 – Mobile DMR (Diamond SG7900 + DIY GPS) — now for sale

  • HONGKAIDE DM9100 – Repaired and now operational on the desk

    Knowledge database (in progress):
    https://github.com/Telectroboy/HongKaide-DM9100-Knowledge-Database

  • QRP Labs QMX+ + ATU-100 – QRP / WSPR beacon
    Nice and easy kit to build.

  • Anytone AT-D578UV Plus (VHF/UHF/DMR/GPS/AirBand)
    Bought defective — VHF PA (NXP AFT05MP075N) was dead.
    Now delivering solid 50 W.

  • 2× UV-K5 – Local use (CEC HF board + custom firmware)

  • Baofeng TK11(8)

Special thanks to F4EPR for my very first HF QSO — and first CW contact.

First CW calls made with only 5 W, then 10 W.

HF Antennas

EFHW – 40 m wire @ 4 m height

  • 49:1 balun using two stacked FT240-43 Fair-Rite cores
  • Planning tests with 2643251002 Fair-Rite ferrite for improvement

Second EFHW – 20 m wire for QRP (QMX+)

Satellite Antenna

Bi-band VHF/UHF tape-measure Yagi (no duplexer).
3D printable adaptable parts available (OnShape).

Original design:
https://www.qsl.net/dk7zb/Duoband/duoband_2-70_2-3.htm

Modified for tape-measure elements by F4EGM.

Dimensions

  • VHF reflector: 102.3 cm (position 0)
  • UHF reflector: 32 cm (23 cm from VHF reflector, center-to-center)
  • VHF radiator: 94.6 cm (including 9 mm gap), 37.2 cm spacing
  • UHF radiator: 32.2 cm (approx. 40 cm from VHF reflector)
  • UHF director: 29.8 cm (50 cm from VHF reflector)

6 turns of RG58 choke on boom.

VHF tuning: excellent.
UHF: good but SWR could be improved.

VHF / UHF Antennas

  • Genuine Diamond SG7900 (mobile) + smaller SG770
  • OM-made omnidirectional antenna (VK2ZOI design, 3D parts available)
  • X510N installed at 8 m AGL (ASL 180 m)
  • 3× ½λ J-Pole (8 mm copper tube) – working but mechanically flexible

Upcoming upgrade: 12 m Spiderbeam mast.

Next project: 3× 5/8 λ VHF ground-plane with radials.

1.7 GHz QFH Antenna

Designed using:
https://jcoppens.com/ant/qfh/calc.en.php

After tuning adjustments, nearly perfect results (confirmed by VNA).

DMR / YSF

MMDVM hotspot (DMR & YSF)

  • Color Code: 1
  • TX: 431.9000 MHz
  • RX: 439.5000 MHz
  • Output power: 10 dBm (ADF7021)

Local hotspot, free to use.

QO-100

  • RX: Bullseye LNB + SDR
  • TX: Remote station (20 W amplifier + AD9363 LibreSDR build in progress)

OpenWebRX+

Password protected:
https://webrx.festival-assistant.fr/

Website & Forum

Digital Modes

  • FT4 / FT8 → PSKReporter
  • WSPR → WSPRnet
  • APRS & ISS-APRS → euro.aprs2.net

QSL accepted via email or eQSL.
Response time may vary.

About Me

I built my first CW keyer at age 10 using wood and a Polaroid cassette spring.
Powered by a 4.5 V battery and two light bulbs, messages were exchanged under a door with my brother.

At 15, I discovered radio via CB (27 MHz).
Since then, radio has never left me.

Active since 1997 on 11 m band.
Early digital modes (SSTV, Packet, PSK31 from 1998).

Former treasurer (10 years) of Sierra-Alpha DX Group.
Now member of:

Professionally:

  • Electronics Engineer (R&D)
  • DevOps / SysOp / Full-Stack / Data & Security manager

Currently working on:

  • Railway antenna experimentation
  • MARCONI H2550 digital radio repairs
  • Custom modular diagnostic test benches

Languages:
French, English (fluent)
Basic Russian, Polish, German, Italian

President of Association Festival-Assistant:
https://www.festival-assistant.fr/

Licensed to operate elevated platforms (“nacelle”), including work in nuclear facilities.

2 m RX Performance (X510N)

(Measurement screenshots available)

73’s and see you on the air!