The Four Metres Website
Home Operating People Equipment Technical Contests Photos Links Forum
Technical
New

70 MHz modification of a MML144/100 by Costas SV1DH

70 MHz low pass filter by Alex IK0VAQ

Big wheel for 70 MHz by Peter OE5MPL and Rudi OE5VRL

Noise and interference from Power Line Transmission/Communication by Nigel G7CNF

FT-847 "C" modification and TX IMD comparison by Geoffrey GI0GDP

Pre-amplifier for 70 MHz by David G3PTU

Active Band Pass Filter for Yaesu FT-847 by Tony CT1FFU

Interfacing Icom HF sets with the Spectrum transv. by Alex GD3UMW

MMANA analysis of the Vinecom 6N4 antenna by Marcel F5DQK

MMANA analysis of the Trident TA4M4L antenna by Marcel F5DQK

50/70 MHz dual band antenna comparison by Uffe PA5DD

160 W MOSFET PA by Geoffrey GI0GDP

FT-221R modifications by Geoffrey GI0GDP

Antennas

A "Hen-Tenna" for 4 m by David G4UNB

70 MHz Yamag antenna by Pino IK0SMG

70 MHz kit for I0JXX's 50 MHz antenna by Marco IW0FFK

Vertical half-wave aerials for 4 m by Ross G6GVI

A Moxon rectangle antenna for 4 m by Ross G6GVI

A "J-pole" half-wave vertical for 4 m converted from a "silver-rod" CB antenna.

A "Slim-Jim" half-wave vertical for 4 m made from 300-ohm ribbon cable.

A centre-fed "co-axial" dipole for 4 m by Tony Hawker G4CJZ

A comparison of commercial 4 m verticals by Ian G6TGO

A 5-element beam for Four by John G0JJL

70 MHz Low Temperature Antennas by Popa Ljubisa YU7EF

A comparison of commercial 4 m yagis using the MMANA simulator by Marcel Pertus F5DQK

Improvements to the YG5-4 antenna by Marcel Pertus F5DQK

Transmitters, etc.

70 MHz modifications for the ICOM IC-502 by Pino IK0SMG

70 MHz modifications for the ICOM IC-706 by Marco IW0FFK

Yaesu FT-847 70 MHz filter simulations and modifications by Marc Vlemmings PA1O

Crossband operation with a transverter made easy by Peter Gouweleeuw PA2V

A 75W solid-state PA for 70 MHz by Geoff Pike GI0GDP

Modification and verification of the FT847 to optimize 70 MHz performance by Keith G4FUF

A further study of the spurious emissions from an FT847 on 70 MHz by Nige Coleman G7CNF

Measurements on an FT-847 transmitter on 70 MHz by Bo Christensen OZ1DJJ

Conversion of the BREMI BRL-200 amplifier to 4 m by Ian M0BCG

A home-built low-pass filter for 4 m by Tony Hawker G4CJZ

A simple antenna tuner for 4 m by Tony Hawker G4CJZ



Login Panel
Username (i.e. Callsign):
Password:
Remember Me

Not registered?
Register now!

Forgot your password?
Latest News
United Arab Emirates on 4 m

Spain continues on 4 m

70 MHz demonstration 24 June 12 UTC

Italy finally on 4 m in 2010

Slovakia continues temp but new allocation

San Marino on 4 m

Italy is soon back on 4 m

WE9XFT radio science beacon

Romania on 4 m

Estonia general release of 4 m, allocation and power

Site maintained by Stewart GM4AFF, Bo OZ2M and David G4ASR
Login problems should be reported to 70mhz Webmaster
The views and opinions expressed on this website are those of the authors only.
Website Created by Subdreamer CMS