Kansas City DX Club

Home of the Annual Dayton CW Pileup Competition

The Basics
Meetings
- Dates, Location and Programs
- Minutes
Activities
CW Pileup Competition
DXing
Contesting
- Resources and Calendar
Members
From the Members
And More...
- W0DXCC 2011

February 27, 2017
Kansas City DX Club Meeting Minutes
Carmack Community Room, Central Resource Library
Overland Park, KS
The February 2017 meeting of the Kansas City DX Club was called to order by President Jeff Blaine, AC0 C, at 6:07 pm CDT (0007 February 28, 2017 UTC).
Agenda -

Introductions/Greeting
Special announcements
DXing and Contesting
Presentation of QST Cover Plaque award to Ralph Crumrine, N0KC
Presentation by Ralph Crumrine of his Award Winning HF Amplifier and Switch-Mode HV Power supply designs in QST Magazine
Shack of the Month

Introductions -
As customary, we all introduced ourselves to the group.
Dick Posz, AE0K, long time member but has not attended for some time was introduced as a visitor. Returning visitor Mansoor Qureshi, AP2MQ, was also introduced and he now has a US call sign KE0MDP. Congratulations Mansoor. (Secretary note: I busted Mansoor’s callsign in the January meeting minutes due to a cut and paste error. My apologies Mansoor.)
Announcements

Dues are due. ($20 to AB0X).
If you need or you know of someone who needs a ride to our meetings let Jeff know. We would like to make sure everyone who wishes to attend can do so.

DXing and Contesting

DXing for March –

Lots of good stuff coming but may be difficult to work
S21GM and S21 KW           Bangladesh
9N7EI and 9N1MD              Nepal
5U5R                                      Niger
9G5X                                      Ghana
and others

Contesting for March -

Lots of QSO Parties
ARRL DX SSB
Ukraine RTTY
CQ World Wide Prefix SSB
Crumrine Cowan Presentation of ARRL QST Magazine Cover Award Plaque to Ralph Crumrine, N0KC, by ARRL Kansas Section Manager, Ron Cowan, KB0DTI, for Ralph’s Switch-Mode High Voltage Power Supply January 2017 QST Article.

Presentation – Ralph Crumrine N0 KC – Describing December 2014 Centennial HF Amplifier and January 2017 Switch-Mode High Voltage Power Supply Designs
Centennial Amplifier –

Plate choke constructed on 100 year old technology ceramic electrical wiring tube insulator gave excellent self resonance characteristics over the bands included and could be air cooled
Printed Circuit band switch construction
Additional high voltage capacitor switching accomplished with hobby solenoids
Separate HF and 6 meter inputs/outputs
Banana jack high voltage terminals (6kv rating)
Warm up functions / over current shutdown
New grid stabilization circuitry built on tube socket described in a September 2003 QEX article
Simple sheet metal construction

Switch-Mode High Voltage Power Supply –

240 VAC 14 Amps input, 3300 VDC 0.9 Amps output
Switch-Mode works at 60kHz allowing very lightweight power transformer which is the heart of the design
Silicon Carbide semiconductors
Discussed importance of a high transformer K (coupling) factor. Ralph achieved K=0.9875 where 1.0 is ideal. A K of 0.93 is poor and would not work.
Transformer has three secondary windings, each with own bridge rectifier
5% load/no load regulation with no feedback voltage regulation needed
Constructed on single 7.5” x 10” PC Board
50us shutdown

Next meeting we hope to have Dragan, K0AP do his ham history presentation.
Jeff showed photos of UX7ID shack which includes a lot of home built gear. Take a look at his QRZ.com page.
As usual Jeff solicited for speakers and ideas for future meetings. Also newsletter content and suggestions are wanted. Send to Mike, AB0X.
The March 2017 club meeting is tentatively scheduled for Monday March 27 at 6:00pm at the Johnson County Central Library. Check later information to confirm.
Charles Hett, K0THN, KCDX Club Secretary