[CQ-Contest] W3NQN Bandpass Filters (Was: Re: 419bandpassfilters..

Marijan Miletic', S56A s56a at bit.si
Sun Apr 1 12:47:03 EDT 2007

W0UN: The Dunestar filters are NOT  7-pole but rather  3-pole designs.

John, thanks for pointing my error!  I am surprised with Dunestar modesty as they can claim 4 poles thanks to series resonances of losely taped inductor and capacitor combination.  Applying the same rule to W3NQN, much better 8 poles might be considered at the cost of two additional serial inductors.  I preffer to transfer RF energy at high voltage with a single capacitor.  

Jukka, 10 m ICE BPF has only 16 db attenuation on 15 m.  Even worse is only 11 dB attenuation of 15 m ICE BPF of 10 m signals.  Your antennas are obviously spaced enough.

Another numerical mistake I made in my last post was on DL2NBU RX filters operating at 50/9 = 5,5 Ohms.

It was nice weekend with 9A hamfest and my tech presentation.

73 de Mario, S56A, N1YU

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