Cookies help us deliver our services.

We may use session cookies for technical purposes such as to enable better navigation through
the site, or to allow you to customize your preferences for interacting with the site.

By using our services, you agree to our use of cookies. OK
home QRZCQ - The database for radio hams 
 
2024-03-28 13:34:56 UTC
 

Call:

   Advanced
 

Call:

  

Pass:

  
 

or

 
G3JKF

Active QRZCQ.com user

activity index: 1 of 5

Ken Franklin

BN25 2EW SEAFORD
England

EU
england
image of g3jkf

Call data

Last update:2023-11-25 15:14:48
Continent:EU
Views:271
Main prefix:G
Latitude:50.7807611
Longitude:0.1000506
Locator:JO00BS
IOTA:EU-005
DXCC Zone:223
ITU Zone:27
CQ Zone:14

QSL data

eQSL QSL:no
Bureau QSL:no
Direct QSL:no
LoTW QSL:no

Biography



G3JKF Biography:

First licensed 1952 when serving in RAF and located in Exeter, Devon.

Operated from Hendon, London after demob in 1954, then from new QTH in Ealing, London.

Relocated to Crawley, Sussex in 1959 and founder member of Crawley Amateur Radio Club in that year.

Initially resident in Gossops Green but moved to Furnace Green in 1963.

Operated all HF bands CW/SSB using Inverted V Dipole and 3 el MP33 tribander at 45ft height.

Worked in Crawley for whole of electronic engineering career but travelled widely for Redifon Flight Simulators on radar simulation projects, then mobile data transmission systems with CYFAS before transferring to MEL on development of airborne radar equipment.

Moved to Seaford on retirement 1998 and now active on HF with Icom IC7600 experimenting with small loop arrays.

Equipment

Only Antenna at G3JKF is LF Triple Loop Array covering 80m to 20m with maximum height 16ft, telescopes to ground level for maintenance. New extra mode added in 2021 to provide Primary coverage 80m to 20m as Loop Antenna and Secondary Vertical in conjunction with ground radials covering 30m to 10m.

For more technical information, including pictures and modelling data, a pdf document describing the design and construction of these antennas is posted on Dropbox as a working document which will be updated occasionally. Dropbox Reference: https://www.dropbox.com/s/wwi7y9yvogq4jhz/Triple%20Loop%20Array%2012%20Issue%201.pdf?dl=0

Currently on WSPR mode with LF Triple Broadside Loop array for 80m to 20m, about the size of a 10m Cubical Quad, at 16ft maximum height, and a HF Triple Broadside Loop array covering 40m to 10m, about 3 ft cube in size, at a maximum height of 16ft. Non-rotatable pairs of wire radials below the HF Triple Loop antenna relay selectable for 17m, 15m, 12m or 10m improve antenna elevation pattern for improved low angle gain 17m through to 10m.

Each antenna tuned by single stepper motor driven vacuum capacitor at the top of the array remotely controlled from shack.

Manual tuning selectable to either loop array using steppers as open loop velocity servos, or open loop automatic tuning to loop SWR null. Stepper motors operate at normal speed for tuning, microstepping near resonance. Tuning time end to end 15 - 20 seconds.

At night use can use battery powered or AC mains PSU driven WSPRlite unit plus Amplifier at 5W output for WSPR Tx operation, generally on 80m, into the LF Triple Loop Antenna.

Loop Antenna Control Unit home designed and constructed. Antenna development aided by use of EZNEC v5 modelling and SARK110 Antenna Analyser.

In 2021 added 2nd mode to the LF Triple Loop Antenna. Modified antenna to provide switchable change to convert the structure to a Vertical Antenna covering all bands 160m to 10m in conjunction with link to multiple earths at base of timber mast and wire radials on ground. This LV addition primarily to give the same frequency coverage as the small HF Triple Loop Antenna. The Vertical uses same feeder as the LF Triple Loop with remote automatic tuning of the Vertical at the antenna using a N7DDC Tuner. Sometimes different Callsign g3jkf/a used when Vertical being compared against the other antennas.

The HF Triple Loop Antenna has been dismantled since the LV Vertical replaces all its bands efficiently and in a more compact form.

Other images

second pic
G3JKF / Pic 2
  

Rev. 76d955ecd7