Episode 384 – Geoffrey Mendenhall – W8GNM


Geoffrey Mendenhall, W8GNMs,  early interest in electronics, germanium transistors, and later high power triodes led him to a career, as an engineer,  designing, building, and managing broadcast transmitters projects for Gates Radio and later Harris Broadcast.  Geoff made a presentation in the last QSO Today Virtual Ham Expo on Beverage Antennas, urging us to try building Beverages  even if conditions are not optimal, and being surprised by the result.  W8GNM is my QSO Today.


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Hometown: Johnstown, PA

Clide May, W3NDO
Bill Orr, W6SAI

First License: Oct 1961 Age 14, KN3VLN
Upgrade Technician
General K3VLN

QTH:  Catawba Island, Ohio

Geoff’s Cayman Island Callsign: ZF2CQ

Favorite Operating Mode: SSB 


Current Rig: 
Flex 6600M HF Transceiver
FlexRadio PGXL Power Genius Linear Amplifier
Home Brew AMP  – 2 X 3500Z Triodes
Tokyo HL 1.5 KFX Amplifier
Heil PR40 Microphone
Symmetric Preamplifiers
Heil Proset Plus with Boom Microphone
Orban Optimod AM Broadcast Processor
Icom IC-756 Pro II
Icom IC-706 HF Transceiver
Harris MS15 FM Exciter

7 in 1 Electronics Kit Olson Electronics
6SN7 Triode
6AG7 Vacuum Tube 
BC-807 Transistor
Knight Kit T-150 Transmitter
Double Sideband Suppressed Carrier
High School Shop Classes
Science Fairs
National Science Fair
Radio Control Bus
6 Meter Linear Amplifier
4-400A Vacuum Tube
Grounded Grid Amplifier
Active Screen Bias
Bill Orr, W6SAI
Eimac Corporation
NAB – National Association of Broadcasters
Raytheon CK722 Germanium Transistors
Raytheon Applications 
Georgia Tech, Atlanta, BSE
WAGA TV Atlanta
CBS News
Georgia Tech WREK FM Station
425 Watt FM Broadcast Transmitter
WTOP Washington
4CX300Y Ceramic Tetrode
Eastern Airlines
8 Bay FM Broadcast Antenna 
W4AQL Georgia Tech Amateur Radio Club
Comco Div of EF Johnson, Coral Gables, FL
Dual Gate MOSFET
National Airlines Boeing 747
Wackenhut Protective Systems
American Electronics Labs
RCA, Meadowlands
Gates Radio, Quincy, IL
Parker Gates, founder of Gates Radio
IF Modulation
Hilmer Swanson, Inventor of Modern AM Modulation Techniques
Step Modulation Broadcast
DF Digital Modulation Scheme
ATSC Version 1 Digital TV Signal
OFDM Modulation
DRM HF Broadcasting
Voice of America, VOA
Art Collins, W0CXX, founder of Collins Radio
Broadcast Electronics, Inc.
Folded Half-Wave Cavity
National Association of Broadcasters Handbook
Greater Cincinnati Amateur Radio Association 
FT-8 Digital Mode
HP Network Analyzer
Hamtech 1 Ghz Sample – need reference
9 Band DXCC
Mt. Athos SV2RSG/A
BevFlex Antenna System
Beverage Antenna
Flag Antenna
Gary Sutcliffe, W9XT
SDR Radio
Scuba Diving 
STEM Programs

Greatest challenge facing amateur radio now:  getting the next generation of young people to become hams

Excited most by: Groups, chasing DX, 1936 Net every week, and annual AM night, along with building, measuring and optimizing. 

Advice to new or returning hams: investigate new operating modes including digital, and learn about SDR (software defined radio).  

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FlexRadio 6600M HF Transceiver

Tokyo HL-1.5 KFX Amplifier

Icom IC-756 ProII HF Transceiver

Icom IC-706 MKII HF Transceiver

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