Marietta, Georgia, USA


I am always building something for audio, computer, or radio. Some of my projects are listed below.

A little web toy I made to show me which grids I have confirmed on 6 meters (07/17)
and the version I made for the ARRL International Grid Chase. (11/17)

A Bluetooth Serial Port for my KX3 (08/16)

N1MM View a dashboard for ARRL Field Day (on github.com) (06/16)

Testing KX3 Switching Power Supplies (01/15)

Measuring SDR Receiver Delay (05/16)

N1KDO "naught" timer. (on hackaday.io) (09/2014)

Yaesu FT-60R Battery Hack (09/14)

N1KDO's LoTW Look Android Smartphone App (08/14)

A G0KSC 5 Element 2-Meter LFA (08/14)

Lightning Disaster and Remediation (02/13)

Some Baluns and Ununs I have built (05/16)

Field Day Bandpass Filters (06/14)

Inverter Generator EMI Filter for Field Day (05/14)

"Direct Box" to run pro audio gear into my IC-746 Pro (05/14)

A digtally operated analog clock made from a meter Not really ham radio related, but... (05/14)

Built a Ten-Tec T-Kit 1230, a 220 MHz transceiver kit. This is another great kit from T-Kit, but like the 6-meter 1260, it is not for the beginning kitbuilder. (ca. 1998)

Designed the NHRC-2 (OLD) a new very-low-cost repeater controller. An article describing this controller appeared in the February 1997 QST Magazine. (1997 and newer)

The NHRC-1 (OLD) Repeater Controller (1993)

N1KDO's 6M Repeater on 53.21 (04/2001)

N1KDO's 70cm Repeater on 442.05 (04/2001)

Conversion of Standard C966 commercial rig to 6-meters (Major PLL butchery) (1995)

Conversion of E. F. Johnson MT584 UHF Mobile Telephones to Disaster Site Portable Repeater (Synth and Exciter hacking). (OLD) Uses WB1EWS's excellent software on the IMTS control board to become a repeater with no add-on controller. Also have hacked these beasties into spiffy full-duplex link radios. (1995)

Construction of 6 Meter antennas (including a sleeve dipole to hang in a tree, which basically sucked, and a 300-ohm twinlead j-pole, which works surprisingly well with 100 watts of RF into it...)

Built a quick-charger for my FT530. The schematic is available in Postscript and Acrobat(.PDF) format. Hacked a copy of this puppy onto the bottom of a charger cup; made a drop in charger for my FT40. (1994)

Construction of low-end repeater controller for portable repeaters and links. Uses a basic stamp. Here's the schematics and the source code. (1995)

Production of HamExam, Amateur Radio examination training software. (02/97)

Repeater System Construction for Atlanta Community Amateur Radio Emergency Services. (C.A.R.E.S.) (1995)

I wrote this paper -- Using a Directional Wattmeter to measure VSWR -- for a technical writing class I took.(02/1997)

Built a Ten-Tec T-Kit 1260 (OLD), 6-Meter FM Transceiver. Get yours today! This is a great kit, fun to build, and easy to operate. I do not recommend this kit for a first-time kit builder. This kit involves hundreds of individual components, and I expect nearly 1000 solder connections. It requires intermediate or better assembly skills. Took me about 25 hours to build. Now for the amplifier...


160M - 70cm, all modes.


Yaesu FT-8900R quad-band in the car, and one in my shack, too.

Icom IC-706 MK II

Elecraft KX-3

Elecraft K-Line home station

Elecraft K-3 field radio


It's finally here! N1KDO's Appliance Operator Page (06/1997)

Use N1KDO's Mathematical Tools for Power (12/1996, 01/2016)

N1KDO's VX-5R Crib Sheet, PDF (02/2000)

NHRC WWW Home Page (10/2013 or newer)

NHRC MASTR II InfoSite (12/2004)

It's back! WorldClock, A multi-timezone digital clock. (1995 and 2014)

A Geographic Information System for Line-of-Sight Radio Communications (03/2008)

hpcap a print interceptor for your test equipment that emits PCL5 image data over a serial port (04/2013)

tdsdump a print interceptor for your Tek TDS Oscilloscope (11/2010)

Speaker Building! (ca. 1999)

E.F. Johnson MT-584 IMTS Mobile Telephone page (01/2002)

My version of the WB5WPA 6M Heliax Duplexer (11/2006)

Marietta House Tower Erection log (12/2003)

Jeff's resume (2016)


ARRL logo
ARRL Life Member
RSGB logo
RSGB Member
NFARL logo
NFARL Member
SEDXC logo
DX Club
ARRL Volunteer Examiner


Use this link to send N1KDO feedback on this web site.

Send a "QSL", or other feedback, for N1KDO's Web QTH (09/2014)