HOME  |  ARTICLESBAND CONDITIONS  |  EQUIPMENT  |  LINK  | MAIL   |  OPERATIONAL  |  PROJECTS  |  REPAIRS & MODS
      HOME  > PROJECT > ALTERNATE CONFIGURATIONS >
MARCONI 'L' ANTENNA CONFIGURATION

Adapting the main HF Doublet Antenna as L Antenna is achieved by simple connecting to one side of the ladder line in the shack directly to the T-Match antenna tuner.


The main HF antenna is an All Band Doublet fed with ladder line and matched with a T-Match antenna tuner including a 1:4 current balun giving access to all HF band including the 160m band. With a view to get better performance particularly on lower frequency bands this antenna was reconfigured as a type of L Antenna by connecting to one side of the ladder line in the shack directly to the T-Match antenna tuner

This antenna requires a counterpoise to work well and this will achieved at least initially by using the galvanized building roof to serve this purpose.  

Fig 1 Multi-band dipole antenna configured as a type of 'L" Antenna. Note left side of the antenna and feed line not connected.

 

Basic All Band Dipole Arrangement

(1)  Inverted 'V' Dipole 42Mtr total length

(2)  450 Ohm Ladder Line 8Mtr length.

(3)  Junction box (Ladder line - twin heliax interface)

(4)  Twin heliax 3.5Mtr length.

(5)  Twin SO259 bulkhead sockets

(6)  T-Match Tuner. See T-Match Tuner

(7)  VSWR Meter.

(8)  HF Transceiver.

 

Photo#1 Junction box (Ladder line - twin heliax interface)

Photo#2 Junction box (Ladder line - twin heliax interface) assembly

Photo#3 Twin SO259 bulkhead sockets

Photo#1 Junction box (Ladder line - twin heliax interface) Photo#2 Junction box (Ladder line - twin heliax interface) assembly Photo#3 Twin SO259 bulkhead sockets and Ground connection.

 

Antenna Modelling with MMANA-GAL

 

Fig 2 All Band Doublet modelled with MMANA-GAL in the normal configuration at 1.825MHz.

 

Fig 3 All Band Doublet re-configured to a 'L' Antenna and modelled with MMANA-GAL at 1.825MHz.

 

 

TOP OF PAGE

Page last revised 24 September, 2017  
 

ACTIVITIES | ARTICLES | EQUIPMENT | HOMELINK | MAIL | PROJECTS

Web design by Peter Miles

All content may be used for unlimited distribution with credits.

This site has been designed to cater for 800 x 600 resolution.
Site is best viewed with Internet Explorer 5.5 or Netscape 6 or higher.