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Amateur Radio


Shack, Antennas

Why Your Filter is Not Working

Have technology from space aliens & NSA - yet I still can't filter the guy up the band!


A Couple of SX-101A Plots

A look at filtering and drift on a classic


YG-455C-1 for the TS-830S

Adopting the YG-455C-1 for use in the Kenwood TS-830S 2nd IF


Kenwood TS-820S

My 1977 dream rig - now joining the shack lineup.  Details on the rig and mods, of course, here.


OCXO for the IF-2000

Tame the drift from the RFSPACE IF-2000 with this simple OCXO conversion


DMU Bandscope Repair

A cure for the bandscope blues here



FT-9000 Roofing Filters for the FT-2000 Sub Rx?

VNA plots of roofing filters found in the main RX of the FT-9000, and the sub RX of the FT-5000.  What does this mean for the FT-2000?  Now  with DR3 measurements!


FT-2000 Sub RX AF Mod

Quiet down the weak signal hiss from the second RX with this easy mod ...


FT-2000 Front End Protection

Yaesu has made some changes to the front end protection circuits.  See the details here.


FT-2000 DSP Filter Characteristics

Plots of the DSP filter. As well as an investigation into the magic behind APF.  And how about CONTOUR?  It's all here!


Combo Analog-Digital Filter

A blend of classic and modern audio filtering for the hybrid rigs in the shack


A Walk Down CW Keyer Lane

For want of an old-school WPM display, the journey can be long indeed


DDS Sidetone

MFK keyer mod makes sweet music of the CW variety


Larcan 1KW 6m SS Amp

Just in time for 6m DX!


RX Antenna Switching

Just part of what's behind door #1.


Tower for 6m/12m/17m 

Mixes WARC antennas, a tilt-up tower - and a basketball goal!



Clifton Labs Z10023B

Got BC IMD?  The latest HPF from K8ZOA is the answer


From Attic to Acres

New country QTH brings a new shack and antennas.  Follow the progress here.



Stealth Attic Array Beam Rebuilds

Featured in Sept 2011 QST and 

NCJ May/June 2012


Shack Automation -
 Field Day Style

(PDF 2MB download) Automatic band decoding, antenna switching triplexer and BPF all in one



So2r BPF Compared

How the 5B4AGN, Dunestar 600 and Array Filtermax measure up


2.4 KHz Roofing Filter

by Network Sciences 
For the Yaesu
FT-2000 and FT-950


No production planned

Click HERE for more details

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