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home QRZCQ - The database for radio hams 
 
2024-03-28 23:18:23 UTC
 

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K0ZR

Active QRZCQ.com user

activity index: 0 of 5
sticker

Jeff Crawford

Purcellville 20132
United States, VA

NA
united states
image of k0zr

Call data

Last update:2022-12-12 02:38:00
Continent:NA
Views:3047
Main prefix:K
Class:Extra
Federal state:VA
US county:Loudoun
Latitude:39.0726375
Longitude:-77.7457004
Locator:FM19DB
DXCC Zone:291
ITU Zone:8
CQ Zone:5
Website:www.k0zr.com
ULS record:232488

Most used bands

40m
(30%)
20m
(25%)
15m
(16%)
80m
(13%)
160m
(10%)

Most used modes

CW
(91%)
SSB
(10%)

QSL data

Last update:2022-12-12 02:37:08
eQSL QSL:YES
Bureau QSL:no
Direct QSL:no
LoTW QSL:YES

Biography

I am an electrical engineer by day and an amateur operator as much of the remainder of the day as possible. My principle areas of specialization are in digital communications, RF, and microwave hardware and systems.

Increasingly I add to my station through my other interests in steel work. I have built my operating desk, tower raising/lowering fixture, base for the 80m free-standing vertical, and other miscellaneous fixtures to hold/store aluminum tubing and other antennas. During 2017-2018 I designed and constructed 2 KW bandpass filters for each of the six contest bands. Each design is different but most of them are 5th-order elliptic bandpass types. Within the past year I have constructed a 90 foot tower using Rohn 45. Sitting at the top is a rotatable Cushcraft XM240 and then yagis fixed on the Caribbean for 10m, 15m, and 20m. These latter three fixed yagis are instantly selectable through the use of remote controlled 1x2 RF switches.

I anticipate publishing a 250+ page book on the design and construction of 2 KW HF bandpass filters in early 2023. In-depth design techniques are reviewed for two filters, 40m and 15m, designed from start-to-finish in two different chapters. Over 200 illustrations, some 30 tables of information, and hundreds of equations comprise the text. The first two-thirds of the book is more "how you do it" with the last third delving into the real engineering involved with Norton transforms, JK inverters and the like.

Worked DXCCs:

Equipment

Very briefly, I operate almost exclusively CW on the HF bands. Antennas include Force12 C31XR for 10, 15, and 20m at a height of 22m and a Cushcraft XM-240 for 40m 28m high on a second guyed tower. Also in use is a ~ 60 ft free-standing vertical with 90 radials for 80m and inverted-L at 80 ft for 160m. The DX Engineering active antenna four-square is used for receive on 160m and 80m.

Station equipment includes Elecraft K3 and ACOM 2000A amplifier, and an Elecraft K3S and Elecraft KPA-1500 amplifier. I use a Bandpasser II filter on each radio and following each amplifier is a K0ZR-designed and constructed band-specific 2 KW bandpass filter. I use the Array Solutions 2 x 8 remote RF switch to complete my SO2R station. As mentioned above, I have instantly switchable yagis by using remote controlled 1x2 RF switches for 10m, 15m, and 20m with each oriented toward the Caribbean.

Other images

second pic
K0ZR / Pic 2
  

Rev. 76d955ecd7