Kongsfjord - 70°43'N 29°21'E

Collection of useful modifications and projects
by Dallas Lankford (1942-2020)

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Antennas and preamplifiers

DX-peditions

Software Defined Receivers

Antenna phasers

Hammarlund

Racal

Audio Processing

Icom

Telefunken

Collins

Japan Radio Company

Watkins-Johnson

Antennas and preamplifiers

2SNL Loop Arrays   331 kB 31-MAR-2011
Capacitor Terminated Loop Arrays 129 kB 10-OCT-2010
Close Spaced Phased MW Vertical Receiving Antennas   122 kB 22-SEP-2007
Common Base Transformer Feedback Norton Amplifiers 1.7 MB 8-JUN-1994
Dual And Quad MW PPL Flag Arrays   517 kB 24-MAR-2011
Dual Staggered Offset Beverage Arrays 282 kB 9-MAY-2011
Flag Theory II   499 kB 20-NOV-2010
High Performance 100' Spaced Dual Active Delta Flag Array 419 kB 2-MAY-2011
High Reverse Isolation Push-Pull Norton-Rohde Feedback Amplifiers  78 kB 5-NOV-2009
High Z PPL's Loop And Flag Arrays   1,2 MB 23-JAN-2011
J310 - J271 High Z Preamp IIP2 Optimization   87 kB 6-APR-2011
Lankford-Ikin-Norton Feedback Amplifiers  342 kB 31-DEC-2010
Low Noise Active Antenna AC/DC Power Supplies 1 MB 26-NOV-2006
Measurements of Some Antennas Signal to Man Made Noise Ratios   913 kB 20-SEP-2006
MW And LW Noise Reducing Antennas  296 kB 21-JUL-2005
MiniFlag and MiniLoop Antennas   177 kB 6-FEB-2011
New MRF581A Transformer Feedback Amplifiers 74 kB 26-AUG-2008
Null Steered QDFAs  234 kB 8-NOV-2009
On Comparing Noise Output Powers Of Amplifiers With Simple Equipment 320 kB  11-JAN-2011
Phased Delta Flag Arrays   2.8 MB 21-FEB-2009
Phased Flag Arrays   125 kB 25-DEC-2008
Some Recent Results For MW Antenna Arrays  65 kB 2-NOV-2009
The Best Small Antennas for MW, LW and SW 249 kB 5-MAY-2008
Variations Of Misek's Center Fed Micro SWA 2 MB 21-AUG-2007
Waller Loop Arrays 473 kB 24-DEC-2010

Antenna phasers

New Improved Passive Phasers 554 kB 2-AUG-2007
Phased MW Receiving Verticals 222 kB 15-AUG-2005

Audio Processing

AM Synchronous Detector Experiences 385 kB 19-JUL-2006
Elliptic Low Pass Audio Filters 678 kB 4-JUL-2005
Audio special: On The Causes And Cures Of Audio Distortion Of Received AM Signal Due To Fading 346 kB 6-FEB-2006

Collins

Collins R-390A: 3TF7 Substitutes 96 kB 24-SEP-2004
Collins R-390A: A new AGC Mod 336 kB 21-JAN-2005
Collins R-390A: AF LF fidelity distortion power modifications 100 kB 5-APR-2004
Collins R-390A: Alignment - from Hollow State Newsletter #29 398 kB JAN-1993
Collins R-390A: BFO fine tuning 310 kB 24-DEC-2003
Collins R-390A: Carrier Meter Mods And Replacing Worn Gain Controls 281 kB 24-SEP-2004
Collins R-390A: Cosmos PTO Linearization 274 kB 10-JUL-2004
Collins R-390A: End Point Alignment and Linearization #1 #2 #3   85-151 kB 20-JAN-2005
Collins R-390A: Full Wave Bridge AM Detector 192 kB 15-FEB-2005
Collins R-390A: ILO AM Synchronous Detector Mod 3 MB 1-JUN-2006
Collins R-390A: Inside the Cosmos PTO 274 kB 6-FEB-2005
Collins R-390A: K5OP Audio Derived AGC Mod 145 kB 8-FEB-2005
Collins R-390A: Noise blanker 425 kB 17-JUL-1995
Collins R-390A: Roofing filters 199 kB 1-SEP-2004
Collins R-390A: Sensitivity measurements 103 kB 7-JUL-2002
Collins R-390A: SSB filters, I & II 402 kB 5-SEP-2004
Collins R-390A: St. Julian Creek Annex R-390A's cracked brown tubulars ... 160 kB 19-JAN-2005

DX-peditions

Grayland Quad Delta Flag Array Report   1.8 MB 2-MAY-2009
Quoddy Head, ME - October 2008 948 kB 21-OCT-2008

Hammarlund

Hammarlund HQ-180(A): AGC Mod 166 kB 6-JUN-1990

Icom

Icom IC-703 Slow AGC Release Mod   185 kB 30-NOV-2005
Icom IC-703 MW and LW Attenuator Removal Mod  
(see also Bjarne Mjelde's impressions of the IC-703 here)		 157 kB 29-NOV-2005
Icom IC-746 Pro: Impressions and mods  
(see also Bjarne Mjelde's impressions here)		 802 kB 13-JUN-2004
Icom IC-746 Pro: Internal Noise Blanker Adjustment 175 kB 27-SEP-2004
Icom IC-746 Pro: Line Out Mod 520 kB 30-OCT-2005

Japan Radio Company

JRC NRD-525: A technical review 184 kB 28-JAN-1993
JRC NRD-525: AM AGC mod 2 179 kB 1-DEC-1992
JRC NRD-525: Filter Leakage 982 kB 15-APR-1993
JRC NRD-525: Narrower Bandwidth Noise Blanker 120 kB 8-JUN-1998
JRC NRD-525: S-meter Damping 267 kB 28-JAN-1993
JRC NRD-92M Noise Problems 348 kB 5-NOV-2002

Software Defined Receivers (SDR)

Perseus Review 
(see also Bjarne Mjelde's impressions here)		 143 kB 2-FEB-2008
SDR-IQ Overload Characteristics 1 MB 14-JAN-2008
SDR-IQ Preamp Mod  390 kB 27-JAN-2008
SDR-IQ Spurs and Intermod  95 kB 29-JAN-2008

Racal

Racal RA6790/GM: A brief review 237 kB 13-DEC-1993
Racal RA6790/GM: AGC modification 363 kB 11-NOV-2004
Racal RA6790/GM: Volume Control Modification 400 kB 18-MAR-2005
Racal RA6793(A): uP Crud Noise Elimination Mod 164 kB 6-FEB-2005
Racal RA6830 Digital S-meter mod 856 kB 21-NOV-2003
Racal RA6830 Encoder shaft mod 161 kB 14-NOV-2003
Racal RA6830JD: Microprocessor Noise Fix 233 kB 13-NOV-2003

Telefunken

Telefunken E 1501 Adventures (see also Bjarne Mjelde's impressions here) 890 kB 13-FEB-2005

Watkins-Johnson

WJ-8711A: Microprocessor noise fix + impressions 266 kB 10-JUN-2004

 

 

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