The North Georgia QRP Club - NoGa "Guppy"

(Genuinely Useful and Practical qrP accessorY)  

The "GUPPY" is a semi-break-in antenna switching unit. The name comes from a North Georgia QRP Club building day hosted by Steve Hudson, AA4BW. The club members built a similar circuit, "Manhattan style", which allowed us to connect our "Transmitter Building Day" transmitters, from Steve’s design to our station receivers. Again, thanks Steve for allowing us to use the GUPPY name.

The circuit board and circuit details are from "W1FB’s QRP Notebook" Published by the ARRL 1991.  Click here for a web album from the NoGa Guppy "Build Day"  of the Manhattan style prototype.

The "Guppy" can be used by itself to interface a homebrew transmitter with your station receiver or transceiver. It can also be used in conjunction with other NoGa kits (the NoGaWatt meter and the NogaPig) to create the ultimate QRP Accessory.

Combining all three kits into one unit will give:

  • Calibrated QRP SWR/Wattmeter with Forward and Reverse meters
  • Switchable Dummy Load.
  • T/R switch with variable T/R delay (including RX mute contacts)
  • Transmit LED
  • Power Indicator Guard (including low voltage indicator, over voltage protection, reverse polarity protection)
  • K8 CW keyer

The "Guppy" includes a circuit board and all board mounted components. It also includes a potentiometer to vary the TR delay time and a LED to indicate when the relay is activated. All other off -board components including the rf connectors and enclosure are to be furnished by the builder.

A .pdf file of  the complete NoGa Guppy Documentation is here.

A .doc file of  the complete NoGa Guppy Documentation is here.


The "Ultimate" Guppy

The implmentation of the "NoGa GuppyWattaPig" uses three of the NoGa kits to build a single QRP accessory. These kits are the NoGaWaTT Meter, the NoGaPiG and the NoGa Guppy.

Joe, W4JHR has put a prototype of the "GuppyWattaPig" together and what a great job he did.   He used a single meter in the SWR/WATT meter section with a switch for forward and reverse.  Depending on how you want to package this kit, you could use both of the meters in the NoGaWaTT kit.  The builder would supply his/her own enclosure.   Joe used a really nice enclosure from the Electronic Goldmine.

Here is what you would have if you were to build a NoGa "GuppyWattaPig":

  • Calibrated QRP SWR/Watt Meter.
  • Switchable dummy load
  • T/R switch with variable T to R delay (extra contacts to ground RX during TX)
  • Transmit LED
  • Power/Indicator Guard
  • K1EL PIC cw keyer (components not included just board layout)
  • Hiss filter (components not included just board layout)

Here are some pictures of the prototype NoGa GuppyWattaPig.  Check out the pictures from "Build Day Two" for a prototype Guppy all by itself.

A parts kit for a solid state "voltage" keyer for rigs such as the TT2 and FireBall40 is available from NoGa.  The kit is called the"Guppette". 

Click HERE for pricing and ordering of all NoGa products..!


Complete GuppyWattaPig in the case.

Front Panel


Rear Panel


Top View.  The PiG Board is on the underside of the large piece of copper clad.  The Guppy board  is toward the top of the picture and the NoGaWaTT board   is toward the bottom.
Open Guppy
Stand alone Guppy in an Altoids Tin.
Closed Guppy
Exterior View of stand alone Guppy.
Naked Guppette
The Guppette.
Mounted Guppette
The Guppette mounted in a prototype Guppy.
2 key jacks on the rear panel.. 1 for normal keying and 1 for voltage keying.

The NoGa GuppyWaTTaPiG special offer includes all 3 of NoGa's electronic kits at a discount. 

This page last update 03/16/2014