Chinese Pixie

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These kits usually come with a 7.023MHz crystal(s) which are in the EXTRA class bands.  Check out our Crystals to move these little rigs to the General Tech/Novice frequencies.

Want to change frequencies?  Try the Pixie Switch to change up to 4 crystals.

Need a Pixie? Get a Pixie, Switch, and Crystals with our CCK-Pixie.

 

Have a neat Pixie tip or hack?  Let us know and we’ll add it to this page.

 

Click here for the Pixie Assembly Manual

Having problems with your Pixie?  Download the Pixie-Troubleshooting screen shots and DC voltages of a typical Pixie.

Follow THIS LINK for a neat enclosure you can build by VE3FWF.

 

Read on for more information about the Pixie including a couple of tips, tricks, mods, and hacks…………..

Pixie2  Pixie-Switch-Mounted

Kit Cost:  $7

Kit Contents:

Bag of Parts, Printed Circuit Board, Schematic Diagram, Parts list and Layout page.

No other instructions

2020 update:  There are several variants of Chinese Pixies now days starting from $3-10:

      • Pixie  with BNC connector (3 ground plane variations but all the same footprint) – This is the version discussed here.
      • Pixie with polarized plugs for the antenna/audio/power/key
      • Pixie with a built in side tone buzzer

Assembly:

Fortunately there are not many parts on this board and no coils to wind.   Assembly was pretty easy by matching up the correct part and soldering in.  Lay the R/C/Q parts in first, then the 8 pin socket, and connectors the last.

Note: These kits may have inventory issues – one kit was missing a 470pF cap.  See the Ocotpus below for other part variances.

Operation and comments:

  • Lead spacing on disc caps should have been either .1″ on the PCB or .2″ parts.
  • Solder pads could have been slightly larger.
  • Ground pins did not have thermals which makes soldering more difficult (bad for VHF RF but were talking 40M here!).
  • Beginners may have problems identifying the inductor values since the color codes are not on the parts list.
  • RIT is a trimmer and should be an outright potentiometer w/ knob.

It works but what more do you want for a $7 kit?  Output power is about 1/2W and receive sensitivity picks up signals so that makes it good for what it is.  The worst part is the wide bandwidth makes tons of high pitches noises which can be annoying after a while.  Best to use an outboard audio filter (see CALF).  Not sure if I will make a QSO with it but will make a nice board for Tx/Rx testing of other projects.

Using FLDigi and HRD software to receive CW works good with this little rig.  Seems no attenuator is needed between the Pixie and computer although the drive can be a little much at times. Found HRD to work slightly better.  YMMV.

2015-02-24 – Finally made a QSO on the Pixie with the 7122 crystals.  Missed Texas the night before with a copy of “SRI NO CPY QRM” returned but managed to work Wisconsin today with a 579.  That’s 280 miles away which makes it 560 miles to the watt!

2015-02-28 – The pixie built by N8JTQ is up and running.  Was missing a 470pF capacitor but it makes and sends CW now!

Pixie Filter Output Values for Other Bands

This is listed in other places on the internet but decided to list them here because I keep loosing my scrap of paper for them.  Use the nearest standard value parts.  For example on 20M a 220pF capacitor should work fine.  In the list below are parts from Tayda Electronics  🙂

160M 1750pF

(Tayda A-4002 1800pF)

4.4uF

(Tayda A-467 4.7uH)

1750pF
80M 894pF

(Tayda A-542 & A-529     820+68pF)

2.23uH

(Tayda A-192 2.2uH)

894pF
40M 470pF

(Tayda A-968 740pF)

1uH

(Tayda A-455 1uH)

470pF
30M 315pF

(Tayda A-4306 or A-537 300/330pF)

.79uH

(Tayda A-444 .68uH)

315pF
20M 226pF

(Tayda A-535 220pF)

.57uH

(Tayda A-442 .56uH)

226pF
17M 176pF

(Tayda A-534 180pF)

.44uH

(Tayda A-41 .47uH)

176pF
15M 151pF

(Tayda A-533 150pF)

.38uH 151pF
12M 127pF

(Tayda A-532 120pF)

.32uH 127pF
10M 113pF

(Tayda A-531 & A-520 100+12pF)

.28uH

(Tayda A-440 .27uH)

113pF
6M 64pF

(Tayda A-4043 62pF)

.16uH 64pF

For 10M & 6M replace the capacitors in the oscillator circuit to 47pF (A-966).

For 80M Add 100pF (A-4170) to C7 to start oscillation.

Using 2N2222 (A-113) or 2N5401 (A-116) transistors may increase power output.

TRANSMIT AUDIO POPPING

One problem with the pixies is the loud popping sound in the earphones when changing between receive and transmit.  Although this mod will not eliminate the popping it will reduce it.  Simply add a pair of back-to-back small signal “switch” type diodes across the headphone jack.  Any type of switching diode will work (1N914, 1N4148, 1N4001, 1N458…..).  You may even find using a pair of Schottkey diodes may further reduce the popping due to it’s lower .35Vturn on voltage.  I used a pair of HSMS-2802 schottkeys as it’s what was in the junk box.

Adding a simple side-tone

The Pixie lacks a simple side-tone and one can be easily added with a Pizeo buzzer and 7.5V 1N4737 Zener Diode.  Simply connect the positive (red) on the buzzer to the positive input voltage terminal on the Pixie.  The connect the banded end of the Zener to the negative (black) on the buzzer.  Finally connect the opposite end of the Zener to the tip of the keying jack.  I used a Tayda A-875 buzzer.  The zener may be optional depending on  your  buzzer.  However in receive there was enough leakage for the buzzer to be lighting audible.  The Zener eliminates this effect.  You may wish to use a little heat shrink tubing to keep the zener from shorting other parts.  You may also wish to add a little cardboard and tape over the piezo hole as it’s a bit loud for my taste.

Thanks to Bernie, VE3FWF, I now have this cool LASER cut enclosure to put it in.

 

Pixie Enclosure w/ Switch

 

Rear View – Replaced transistors

with PZT2222’s for 1W output!

VE3FWF Enclosure Plans (.SVG, .PDF & .JSON files) along with SVXO instructions are available here:

VE3FWF-Enclosures


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