VHF-index of pa0nhc technical HAM pages.
20150407 / 20170623

Since 20150113 this site is located at: http://www.pa0nhc.nl   

EN = read English version article   NL = Nederlands



Nieuwe versie, door professioneel printje makkelijk te bouwen 144 MHz ARDF peil ontvanger.

Optimale ontvanger eigenschappen.
144 - 145,4 MHz.
Zeer gevoelig (0.22 uV AM)
Goede selectiviteit.
Max input 12 mV.
9V @ 17 mA max.
Meeste onderdelen bedraad, reeds gewikkelde spoelen.
Goedkope, afschermende behuizing

Zie ook de 80m versie.
Het professionele dubbelzijdige printje is beschikbaar.

Laatste update : 201711

Last update : 20171112.

The professional double sided PCB is available.
See also the 80m version

New version, using a professional PCB for e
asy building a 144MHz ARDF direction finding receiver.

Optimal receiving properties :
144 - 145.4 MHz.
Very sensitive (0.22 uV AM)
Max input 12 mV.
Very good selectivity.
9V @ 17 mA max.
Most components wired, readily wound coils.
Cheap die cast ALU box.


De oude techniek van de Rotterdamse repeaters
PI3RTD en PI2RTD (ca. 1995-2005)


DIY VHF helix filters. 
Very selective, low insertion loss.

Very cheaply made from paint cans and copper wire.

One to four resonators.
Combinations with coax filters.

145MHz band pass and 160MHz reject.

EN 144 - 435 MHz wideband low-noise hi-IP preamp.
3.5 - 435 MHz directional couplers on a small piece of PCB.
Dependable and accurate.
EN 145MHz ARDF fox hunt antenna. VERY EFFECTIVE and light, proven design.

145MHz repeater duplex filter, made from PCB material and 22mm copper water pipe.
(GW4AKZ and Dirk Rijnenberg constructed one). Republished 20130529

Full theory on (145MHz) cavity filters.  (After a pencil paper from G8AMG)