ILER 20 QRP MODS

My Iler 20 is finally oparational. The IF has changed to 4.000 MHz and the vxo has 10.250 MHz cristals.(Ebay)  The VXO coil now holds 64 turns no.26 (0.31mm) magnet wire and the tuning range with the polyvaricon is 14.129 - 14.246.4 MHz  with a stable signal .    5 capacitors of 10 pF now serve in the 4 MHz cristal filter. As you can see, even the microphone was to bulky and was replaced by a home made model. Audio sounds verry good and the rf power is 6 Watts PEP at 13.8V. Also C28 was lowered to 33nF to get more high tones in the audio output, but that's a question of personal taste. I found a perfect little speaker named : Visaton K 50 WP , 3 Watt 8 Ohm art.nr.:2915 .In order to lift the microphone  input, R6 was changed to 470K. The mini counter comes from Hendricks QRP and was chosen for it's low power consumption and small size . Some humming interference can be caused by the display multiplexer of the counter but a small filter takes care of that:

The cabinet was ordered from Qrp Project in Berlin http://www.qrp-shop.biz/epages/qrp-shop.sf/de_DE/?ObjectPath=/Shops/qrp-shop/Products/Kuehlr168x110x54  It fits the board like a glove . For smooth tuning a 1:10 ball drive is added. Because of the 180 degree tuning range of the polyvaricon, only a 1:5 reduction remains. A series 3000 Multiplex RC transmitter was the donor for the tilt stand, but US builders can find one here :http://www.budwig.com/collapsible-tilt-stands.html
Here is a tuning range video :




The latest boards have a litle bug causing a shortcut to ground of C37 and R22 .This prevents the noisefilter from doing his job.  Before installing C37, take a  mm drill and make a smal cone in the board surface to remove the ground connection .

I noticed that the noise filter even causes the noise levell to rise , so i desided to remove C37 and R22 permanently.

The Iler kits  represent a modern and compact, easy to build alternative, to the Bitx and Taurus.
More info about this nice kit :  http://ea3gcy.blogspot.nl/