This product is made to order by Spectrum Communications. It is not ready built waiting for dispatch.

Slim-G Aerial for 2 metre band operation, receive or transmit.  This is essentially a portable version of the Slim-Jim aerial described by Fred Judd G2BCX in PW April 1978.

The aerial was originally developed as a J pole with a 1/4 wave section one side and a 3/4 wave section the other side.  The two sections are joined at the bottom and the feeder is attached a little way up from the bottom and with the braid side of the coax to the short arm. 

Another 1/2 wave section was added later in parallel with the long arm and connected at the top, with its bottom end a centimetre or two from the top of the short arm.  So the configuration had actually changed from being a squashed J to a squashed G and hence the new name coined by Spectrum.

The later configuration is two 1/2 wave sections in phase over a quarterwave section and has at least 3dB gain over a vertically mounted dipole or a 1/4 wave ground plane antenna.  The radiation and reception pattern is close to omni-directional.

The construction of the Spectrum Communications Slim-G has 300 Ohm ribbon feeder for the aerial element together with a PVC tube with end caps containing a stub board connecting to 4 metres of 50 Ohm RG58U coax, usually terminated with a PL259 plug. If you wish for a BNC plug to be fitted please leave a 'Note to the Seller' requesting it.

The lengths of short arm and long arms have been calculated and cropped that together with the precise positioning of the coax feedpoint on the stub gives an SWR of better than 1.5:1 on transmit at 145MHz.  Power handling is good to at least 50W.

The length of the ribbon beyond the stub tube is 127cm and the stub tube with end caps is 12cm, giving an overall length of 139cm (55 inches).  Weight is about 240g and when folded will fit in a poly bag 22cm by 11cm.  It is intended to be hung vertically from the woven nylon cord supplied and can be used indoors or out but would advise adding a little silicon sealant to the entry points of the twin feeder if the aerial is to be used long term outside.