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W7NX Hawaii flag Hawaii

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I have been licensed since 1979, originally as N7ATM and subsequently held the callsigns: W7NX and KH6NX.

QSL INFO: I enjoy sending and receiving actual QSL cards. LOTW and similar services are fast and easy, but I think a lot of the charm of QSL-ing is lost. So, if you want a paper QSL, I will be happy to respond. Please QSL direct. Via the Buro is okay, but will take longer (I'm way behind. I have all the cards done, but I need to sort and mail them to the ougoing buro). I now update eQSL and QRZ at the same time I update LOTW, about every 2 weeks or so.  

Lastly, a self addressed envelop is welcome but not required. Please do not send money. The honor of a QSO with you is all the payment I want. I always send money back. I worry about mail theft when I do. I want you to receive the QSL card you requested and not have it taken by someone looking for money.

SCHEDULED QSO's: I am happy to try to schedule contacts if you need Hawaii for WAS, or DXCC, or if you are trying to learn Morse code and want to practice. Email me at the address above.

I completed residency training in internal medicine in June 2013, and moved from Oregon to Hawai'i to take a position at a local hospital in Honolulu. Medicine is a second career for me. Previously I was an electrical engineer. I designed high speed computers, cameras, and radios during most of my career. In addition to my medical degree, I also hold a BS and MS in electrical engineering. My engineering graduate work was in RF and microwave engineering and electromagnetics.

I enjoy home brewing, working DX, and I operate mainly CW. I enjoy contesting. If I am not working, I will usually be on the air for all major CW contests. My primary station is an old FT-1000MP. I have an FT-817 and FT-857D for portable work. The primary amp is a Yaesu VL-1000 (Quadra). My backup amp is a Drake L7, which worked flawlessly for years, except for once when one of the capacitors in the power supply exploded in a shower of sparks. This was repaired with a rebuild kit from Harbach Electronics and operation is again flawless. I can highly recommend the L4/L7 power supply rebuild kit they sell, if you are trying to keep one of these great old amps running. My main antenna is 3 element tribander at 40 feet stacked with a 3 element 6M yagi at 45 feet. I have a fixed dipole for 80M at 35 feet and rotatable trap dipole for 40M as part of the tribander.

I recently acquired, repaired and deployed a vintage station consisting of  Drake C-line "Twins:" T-4XC and R-4C, which were originally built in late 1977/early 1978. The receiver had some issues, mainly power supply feedthrough into the 3rd mixer which I spent a whole day tracking down with the spectrum analyzer. I wasn't exactly certain what would be required to fix it so I called Sherwood Engineering and spoke with Rob Sherwood. I ended up purchasing all the "Sherwood Mods." I installed them one at a time (where possible) to see how each changed the performance of the R-4C. While all the modifications improved the receiver, replacement 3rd mixer was what my R-4C needed. The difference was night and day. All of the objectionable mixing products disappeared. I had a lot of fun restoring these great old radios and getting them back on the air. Thanks also go to Rob Sherwood of Sherwood Engineering for his advice, and excellent updates for this receiver. I bought the L4B from a friend (WH7W) here on the island. He was planning to sell it and had not used it for several years. He brought it over to my shack to test it. There it was, sitting next the the C-line... He made me a good deal.

Drake C-line

When I arrived on island, several of the local hams, in particular WH6R, pushed me toward trying vertical antennas at the seashore. Verticals at the shoreline work very well, even QRP. The antenna in the background (below) is a 15M half-wave vertical dipole, end fed, supported on a DK9SQ fiberglass mast (available from www.kangaus.com) and attached with painter's tape (foreground). This antenna is about 6dBi and has a very low angle or radiation (see pattern below). This is important from Hawaii since we are 2500 miles from anywhere. Actually, it is important from anywhere, if you want to work DX.

QRP with toes in the sand on windward Oahu using a vertical "end-fed" dipole

Technically you can't feed the actual end of a dipole, as the current is zero at that point and impedance is infinite. I'm feeding close to the end. The remainder of the dipole is either a small counterpoise, or the coax (not ideal). In this setup I was using a tuning box sold by the Emergency Amateur Radio Club (www.earchi.org) here in Honolulu (unfortunately EARC no longer sells these, so if you are interested and need help designing one, contact me via email). It consists of an L-network with a section of RG-174 as a capacitor and a powdered iron tordoidal inductor. There is no provision on the EARC matching networks for a counterpoise (easily added if desired) thus the coax shield will be used to complete the antenna. The purist in me does not like this approach, but this method works well. It is very fast and easy to set up, in keeping with the EARC charter of emergency preparedness. It could be improved on by addition of a choke to the coax (coil coax several times with 6-8" diameter) a foot or two from the match-box. This will decouple the remainder of the coax from the antenna system.Tuning is by adjustment of wire length. SWR is low and no additional antenna tuner is needed once tuned. I've designed a multiband version of this tuning box that works on 20M-10M. The RG-174 capacitor is replaced with an air variable capacitor and the inductor is tapped and switched with a rotary switch for each of the 5 bands. When I have time, I will document it here.

Sunrise on Kailua Beach

Many of you have commented that you enjoy the sunrise over Kailua beach photo. Here is another from a spot a little farther down the beach. It was taken at sunset.

Moonrise on Kailua Beach

73, and Aloha from Hawai'i - See you on the bands!

Which way to the Radio Room? (Wreck diving in about 100 feet (30m) of water off Waikiki, Oahu, Hawai'i)

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7431354 Last modified: 2016-07-08 20:54:38, 8849 bytes

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QRZ Logbook Summary for - W7NX
Latest Contacts for W7NX at QRZ.com
dedateband mode grid Country op

Book Totals: 0 qso's   0 confirmed Get a free logbook at QRZ.COM

World Continents Award#12714
Granted: 2016-04-29 08:25:02   (KH6NX)

  • 10 Meters Mixed
  • 15 Meters Mixed
  • 20 Meters Mixed
  • 40 Meters Mixed
Grid Squared Award#3540
Granted: 2015-02-16 04:10:02   (KH6NX)

  • 10 Meters CW
  • 15 Meters CW
  • 20 Meters CW
  • 5 Band Mixed
  • 10 Meters Mixed
    15 Meters Mixed
    20 Meters Mixed
    40 Meters Mixed
    80 Meters Mixed
  • 10 Meters Phone
  • 20 Meters Phone
United States Award#646
Granted: 2015-02-16 03:05:04   (KH6NX)

  • 15 Meters Mixed
  • 20 Meters Mixed
  • Mixed CW
  • Mixed Phone
DX World Award#916
Granted: 2015-02-16 03:05:03   (KH6NX)

  • 20 Meters Mixed
  • Mixed CW
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