Paesano Alternate Construction Method
 

Hams are impatient! Most newly minted hams (and some OT's) have this insatiable urge to be credit card warriors and simply contact Amazon and by the end of that day or gulp having to await to the next day --have their thing!

Sometimes that just does not work. For this build I used the Perigrino Circuit Board and to get one you have to conatct the GQRP club sales that have maybe a half dozen or most likely contact the EA QRP club which requires you to joining that club first before getting a board from them.

But there is another way to do this and I am providing you a link that exploits that alternate method.

Our friend Nigel, G0EBQ, has scratch built The Paesano and I am happy to report that it is on the air and he successfully had his first QSO with the rig. Here are some photos of his build.

 

 

A Note from Nigel, G0EBQ

MY POOR MANS PAESANO

 

Nigel Flatman G0EBQ 3375

nigel.flatman@yahoo.com

 

I had built the excellent Peregrino, as featured in the Autumn Sprat, but its main problem is that /p operation isnt very conducive to the British climate, as well as 17m being pretty much just white noise at the moment. So the plan was to make a 20m version to work into a 50 ohm load and to drive a linear.

 

I built a 20m version on breadboard with a 3.20 Mhz IF and 11mhz vxo using cheap club crystals. The receiver worked fine though vxo shift was minimal-I have corresponded with another builder who believes that is due to the particular zener used to drop the voltage to the ICs though we have no idea why! My attempts to make the existing circuitry work into a 50ohm load were a miserable failure and I put it aside “for further investigation at a later date”.

 

I was able to obtain pcbs from EA-QRP for the Peregrino project and amongst those who contacted me was Pete Juliano N6QW; the result was Petes brilliant article called the “Paesano”in the last Sprat. Pete has been incredibly helpful and as a result of exchanging emails I have my simplified version up and running.

 

I dont have an electronics background and don't understand “new” technology such as Arduinos so have used “old school” technology. So I used the vfo from Farhan Ashars original BITX design (1) which is my standard vfo design and is stable and always works for me, adjusting the turns on the coil L4, a T50/6,and the value of the capacitor in series with the bandset trimmer for a 5 Mhz output. I took the output from the buffer transistor marked Q6 via a 10nf capacitor to pin 6 of the mixer U1; however the output was 800mv which was too much for the mixer so had to increase the value of the 4.7k resistor between the two transistors to 27k to reduce the output to about 300mv which was perfect.

 

The Imrad filter that Pete specified is still quite pricey so I used the club 9mhz one.With this though the impedance is 500ohm so as suggested by Pete I used matching transformers of 7t on an FT37-43, tapped at 4t, which worked perfectly. Mine is built on perfboard but if you are using the Peregrino pcbs you will need to adapt the pcb to suit.

 

I retained the existing Peregrino bfo circuit and the P switch for tuneup and changeover is just a simple relay and switch. Other than that I replaced the zener with an 8v regulator as recommended, and used Petes receive rf amp, bandpass filter, low pass filter and tx driver stages with a GQRP club freeby 2N3866 equivalent giving 600mw peak out, these are all superb designs and worked first time. My final remains a work in progress but with just the 600mw I have worked Slovenia and Sweden.The receiver is really hot-the rf amp makes a huge difference-and I have heard Saudi Arabia, Ivory Coast, Asiatic Russia and can hear East Coast Americans most days at good strength.

 

Many thanks again to Pete N6QW for his help and advice

 

References (1) www.phonestack.com/farhan/bitx

This is Nigel's completed Rig. Bravo G0EBQ!!!!

 

See also my website on some construction tools that can be used to build The Paesano!

www.jessystems.com/N6QW's_K_K.html

The methodology uses single sided copper vector board (some know it a perforated board). The method involves a two step process.

  1. Step one is to use a piece of standard perforated board (no copper) to test run a circuit layout similar to a schematic where you best fit the components to minimize cross oveer and jumbled wiring. With a bit of patience and a few tries you can arrive at a compact layout. The advantage of this method is the common ground plane and any connection to ground using the single sided board is simply soldered to the top of the board and all point to point wiring is done on the insulated underside of the board. Once you have arrived at the best fit layout, take a digital photo.
  2. Step two involves transferring from the photo the best fit to the actual copper board. The reason for the two steps is that you want to minimize the handling of the copper board as your finger marks are acidic and will lead to down stream discoloration of the board. I even resort to wearing nitride rubber gloves when I do this step. Because the point to point wiring involves connections on the underside you will need to elevate the board off of the final mounting location. I use 1/4 inch aluminum spacers tapped for 4-40 bolts and nuts.

This is not hard and will lead to a great looking hand made board. The two step process also enables minimizing the actual board footprint so you can have a compact build.