SG-Lab Transverter Antennas

SG-Lab supply a HB9CV PCB yagi antenna with each transverter purchased, it’s a great deal. 🙂     The supplied antennas offer the user the ability to get on air quickly and without a major investment in other antennas and expensive low loss coax.

I use SG-Lab’s 23 and 13cm transverters for the amateur radio Summits on the Air (SOTA) awards program.  The form factor and weight of both transverters is excellent and ideal for SOTA backpack activations.  The supplied 23 and 13cm antennas are fitted with SMA male connectors which can be mounted directly to the transverter RF output female SMA socket.  (see photos)

Transverters and Supplied Antennas

23cm 2el HB9CV PCB Yagi

13cm HB9CV PCB Yagi active elements

13cm 4el HB9CV PCB Yagi

13cm and 23cm HB9CV PCB antennas

One minor issue with mounting the HB9CV yagi directly to the transverter RF output socket is the effect of stray capacitance from the transverter metal case.  In particular when mounting the 13cm antenna to the output socket the stray capacitance changes the impedance of the 13cm HB9CV antenna to the point where the transverter VSWR LED glows red (high VSWR).   How to overcome the stray capacitance?  Well it’s quite simple, here is one solution…

Make a 50 mm (2 inch) semi-rigid RG402 coax extension to move the antenna away from the metal case, whilst maintaining the portability features of the SG-Lab package and keeping feedline losses to a minimum.  😉

Parts:

  • 2 x 50 mm (2 inch) lengths of semi-rigid RG402 50 ohm coax
  • 2 x female SMA sockets (solder type)
  • 2 x male SMA connectors (solder type)
  • length of heat-shrink tube

50 mm semi-rigid 50 ohm RG402 coax assembly

23cm antenna RG402 extension

SG-Lab 23cm transverter and 23cm HB9CV PCB antenna

13cm antenna RG402 extension

SG-Lab 13cm transverter and 13cm HB9CV PCB antenna

Stray capacitive reactance resolved.  Have fun with your SG-Lab 23 and 13cm transverters  🙂

If you are interested in 23cm and 13cm SOTA activations, follow my blog at https://vk1sotaon23cm.wordpress.com/

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