W6IWI, Tucson AZ

We moved from Arvada CO to Tucson AZ in 2021. An archive of the Colorado station is here. This page describes the current station in AZ. Both the page and the station are under construction.




Favorite band, image from the cover of a recent CRHS Journal, an old Schlitz magazine ad, Solar-Terrestrial Data showing conditions for HF and VHF bands and the MUF for Boulder CO, the W6IWI QSL card, view of W6IWI Mobile. The Optimal Working Frequency is about 0.85 times the Maximum Usable Frequency.

Search W6IWI:

The call letters W6IWI were first used by Kauko Hallikainen in the 1930s (1933 license, 1937 ARRL membership). See the 1934, 1936, 1937, and 1938 Amateur Radio Callbook. The 1930s QSL card was similar to that shown above (I may still have one of the originals somewhere). By 1952, the call had been reassigned to Carson Donaldson in Inglewood CA. He held it through 1977. I acquired the call in 2016. Prior to that, I held the call WA6FDN, and prior to that, WN6FDN. The WA6FDN license was first granted in 1969, with WN6FDN in 1968. WA6FDN shows up in the Summer 1969 Callbook. NL7XM offers a great service. He has over 100 years of Radio Amateur Callbooks and will find the first appearance of your callsign in the Callbook. For a reasonable cost, he'll provide certified copies of these pages verifying that the callsign was held by the particular person on this date. This is what he sent me for WN6FDN and WA6FDN.

WN6FDN started with a Heathkit DX-60 transmitter and a National NC-300 receiver running CW on HF. WA6FDN used a Viking Ranger transmitter running AM, CW, and RTTY on HF. RTTY used a Teletype model 15 printer (also see a slow motion video of a model 15 in operationg), and a model 14 typing reperf and transmitter distributor. W6IWI now uses an SEA 245 with a Dentron Clipperton-L amplifier running RTTY, CW and SSB into an inverted L antenna. VHF and UHF FM are covered with a Baofeng UV-5R and a Wouxun KG-UV-6X. The Wouxun KG-UV-6X normally drives an outside vertical antenna at home. Mobile info is here.

HF Station Details

Click in a box in the block diagram for more details. . Your browser does not support the HTML5 canvas tag. ;

Maximum Usable Frequency (15.93 MHz at 27 Jun 2022 1500 GMT)

Every now and then there is a gap in the MUF data received. For example, June 15, 2021 through July 7, 2021.
The graph below plots the Boulder CO MUF and OWF over time (times are local at the browser). Data courtesy of Paul N0NBH. The MUF is the maximum frequency that can be used over a 3,000 km path centered on Boulder CO. The optimal working frequency is 0.85 times the MUF.

The graph shows the MUF and OWF for the past two days. Drag right to see previous values. Use the mouse scroll wheel to zoom in and out. Right click to get back to the original view.

W6IWI HF Activity

The table below shows recent contacts logged on qrz.com.

RBN Report

The table below is generated by a PHP script that pulls JSON data from the Reverse Beacon Network, parses it, calculates distance and bearing based on latitude and longitude, then shows data for the last 250 spots. Frequency changes greater than 1 kHz or time changes greater than 1 hour are shown in bold. The Rx links link to the QRZ page for the station. The SNR links link to a graph of signal to noise ratio versus time for that receiver and band (data limited to 250 spots total from RBN)

The background color is green if the distance is greater than 3,000 miles. The Relative Distance column has a * for every 200 miles.

TimeRxFreq (kHz)SNRModeSpeedRx LocationDistance and BearingRelative Distance
0427z 27 JunKO7SS 14052.0 46 dB CW15 wpmMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0427z 27 JunK9IMM 14052.0 31 dB CW15 wpmMount Horeb, WI2194 km (1363 miles) at 51.3 degrees******
0427z 27 JunW3RGA 14052.0 18 dB CW14 wpmSunbury, PA3176 km (1974 miles) at 62.6 degrees*********
0427z 27 JunKP2RUM 14052.0 20 dB CW15 wpmChristiansted, VI4882 km (3033 miles) at 97.8 degrees***************
0427z 27 JunW8WWV 14052.0 26 dB CW15 wpmChesterland, OH2802 km (1741 miles) at 60 degrees********
0427z 27 JunN7TUG 14052.1 10 dB CW15 wpmSeattle, WA1973 km (1226 miles) at 333.9 degrees******
0427z 27 JunKO7SS-7 14052.0 12 dB CW16 wpmMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0427z 27 JunWE9V 14052.0 36 dB CW16 wpmBristol, WI2310 km (1435 miles) at 53.7 degrees*******
0422z 27 JunW3RGA 14052.0 18 dB CW15 wpmSunbury, PA3176 km (1974 miles) at 62.6 degrees*********
0419z 27 JunKP2RUM 14052.0 19 dB CW15 wpmChristiansted, VI4882 km (3033 miles) at 97.8 degrees***************
0416z 27 JunKO7SS 14052.0 47 dB CW12 wpmMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0416z 27 JunK6FOD 14052.0 12 dB CW12 wpmSouth Pasadena, CA706 km (438 miles) at 289.1 degrees**
0416z 27 JunW3RGA 14052.0 17 dB CW12 wpmSunbury, PA3176 km (1974 miles) at 62.6 degrees*********
0416z 27 JunK7EG 14052.0 13 dB CW12 wpmAuburn, WA1928 km (1198 miles) at 333.7 degrees*****
0416z 27 JunN7TUG 14052.1 14 dB CW12 wpmSeattle, WA1973 km (1226 miles) at 333.9 degrees******
0416z 27 JunW8WWV 14052.0 26 dB CW12 wpmChesterland, OH2802 km (1741 miles) at 60 degrees********
0416z 27 JunTI7W 14052.0 29 dB CW12 wpmGuanacaste, Costa Rica3566 km (2216 miles) at 126.3 degrees***********
0416z 27 JunAC0C-1 14052.0 11 dB CW12 wpmLouisburg, KS1632 km (1014 miles) at 59.6 degrees*****
0416z 27 JunKO7SS-7 14052.0 12 dB CW12 wpmMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0416z 27 JunVE6JY 14052.0 24 dB CW12 wpmLamont, AB2395 km (1488 miles) at 356.9 degrees*******
0416z 27 JunKH6LC 14052.0 20 dB CW12 wpmKeaau, HI4652 km (2890 miles) at 264.3 degrees**************
0416z 27 JunKU7T 14052.0 39 dB CW12 wpmNorth Bend, WA1930 km (1199 miles) at 334.6 degrees*****
0416z 27 JunWF7U 14052.0 24 dB CW12 wpmIssaquah, WA1944 km (1208 miles) at 334.2 degrees******
0416z 27 JunK1TTT 14052.0 19 dB CW12 wpmPeru, MA3499 km (2174 miles) at 60.1 degrees**********
0416z 27 JunVE7CC 14052.0 22 dB CW12 wpmMaple Ridge, BC2120 km (1317 miles) at 336.1 degrees******
0416z 27 JunWE9V 14052.0 30 dB CW12 wpmBristol, WI2310 km (1435 miles) at 53.7 degrees*******
0416z 27 JunK9IMM 14052.0 25 dB CW12 wpmMount Horeb, WI2194 km (1363 miles) at 51.3 degrees******
1811z 26 JunW6YX 14083.9 29 dB RTTY45 bpsStanford, CA1182 km (734 miles) at 302.2 degrees***
1811z 26 JunKO7SS-7 14083.9 26 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
1811z 26 JunKO7SS 14083.9 49 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
1729z 26 JunN6TV 14083.9 12 dB RTTY45 bpsSan Jose, CA1140 km (708 miles) at 302.2 degrees***
1729z 26 JunKO7SS-7 14083.9 26 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
1729z 26 JunWE9V 14083.8 16 dB RTTY45 bpsBristol, WI2310 km (1435 miles) at 53.7 degrees*******
1729z 26 JunKO7SS 14083.9 50 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
1707z 26 JunN6TV 14083.9 10 dB RTTY45 bpsSan Jose, CA1140 km (708 miles) at 302.2 degrees***
1707z 26 JunKE3BK 14083.9 11 dB RTTY45 bpsMountain House, CA1149 km (714 miles) at 305.4 degrees***
1707z 26 JunKO7SS-7 14083.9 27 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
1706z 26 JunW6YX 14083.9 23 dB RTTY45 bpsStanford, CA1182 km (734 miles) at 302.2 degrees***
1706z 26 JunKO7SS 14083.9 51 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
1629z 26 JunK1TTT 14083.9 14 dB RTTY45 bpsPeru, MA3499 km (2174 miles) at 60.1 degrees**********
1629z 26 JunWE9V 14083.8 13 dB RTTY45 bpsBristol, WI2310 km (1435 miles) at 53.7 degrees*******
1629z 26 JunN6TV 14083.9 10 dB RTTY45 bpsSan Jose, CA1140 km (708 miles) at 302.2 degrees***
1629z 26 JunW6YX 14083.9 30 dB RTTY45 bpsStanford, CA1182 km (734 miles) at 302.2 degrees***
1629z 26 JunKO7SS-7 14083.9 27 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
1628z 26 JunKO7SS 14083.9 52 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0456z 26 JunKH6LC 14083.9 15 dB RTTY45 bpsKeaau, HI4652 km (2890 miles) at 264.3 degrees**************
0456z 26 JunK6FOD 14083.9 22 dB RTTY45 bpsSouth Pasadena, CA706 km (438 miles) at 289.1 degrees**
0456z 26 JunK1TTT 14083.9 24 dB RTTY45 bpsPeru, MA3499 km (2174 miles) at 60.1 degrees**********
0456z 26 JunVE7CC 14083.9 32 dB RTTY45 bpsMaple Ridge, BC2120 km (1317 miles) at 336.1 degrees******
0456z 26 JunKO7SS 14083.9 48 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0456z 26 JunWE9V 14083.8 19 dB RTTY45 bpsBristol, WI2310 km (1435 miles) at 53.7 degrees*******
0456z 26 JunKO7SS-7 14083.9 20 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0413z 26 JunW6YX 14083.9 26 dB RTTY45 bpsStanford, CA1182 km (734 miles) at 302.2 degrees***
0413z 26 JunWZ7I 14083.9 13 dB RTTY45 bpsPipersville, PA3304 km (2053 miles) at 63.8 degrees**********
0412z 26 JunN6TV 14083.9 20 dB RTTY45 bpsSan Jose, CA1140 km (708 miles) at 302.2 degrees***
0412z 26 JunKO7SS 14083.9 48 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0412z 26 JunK1TTT 14083.9 20 dB RTTY45 bpsPeru, MA3499 km (2174 miles) at 60.1 degrees**********
0412z 26 JunK6FOD 14083.9 27 dB RTTY45 bpsSouth Pasadena, CA706 km (438 miles) at 289.1 degrees**
0412z 26 JunKH6LC 14083.9 21 dB RTTY45 bpsKeaau, HI4652 km (2890 miles) at 264.3 degrees**************
0412z 26 JunVE7CC 14083.9 35 dB RTTY45 bpsMaple Ridge, BC2120 km (1317 miles) at 336.1 degrees******
0412z 26 JunKO7SS-7 14083.9 21 dB RTTY45 bpsMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0348z 25 JunK6FOD 14052.0 26 dB CW15 wpmSouth Pasadena, CA706 km (438 miles) at 289.1 degrees**
0348z 25 JunKM3T-2 14052.0 22 dB CW14 wpmAmherst, NH3618 km (2248 miles) at 59.6 degrees***********
0348z 25 JunVE2WU 14052.0 21 dB CW14 wpmCovey Hill, QC3469 km (2156 miles) at 55 degrees**********
0348z 25 JunW9XG 14052.0 11 dB CW14 wpmMilan, IL2075 km (1289 miles) at 54.4 degrees******
0347z 25 JunK9TM-4 14052.0 10 dB CW15 wpmSylvania, OH2824 km (1755 miles) at 94.5 degrees********
0346z 25 JunEA8BFK 14052.0 15 dB CW15 wpmIs Canarias, Spain8952 km (5562 miles) at 62.1 degrees***************************
0344z 25 JunTI7W 14052.0 23 dB CW11 wpmGuanacaste, Costa Rica3566 km (2216 miles) at 126.3 degrees***********
0344z 25 JunKH6LC 14052.0 17 dB CW11 wpmKeaau, HI4652 km (2890 miles) at 264.3 degrees**************
0344z 25 JunWF7U 14052.0 17 dB CW12 wpmIssaquah, WA1944 km (1208 miles) at 334.2 degrees******
0344z 25 JunWZ7I 14052.0 14 dB CW12 wpmPipersville, PA3304 km (2053 miles) at 63.8 degrees**********
0344z 25 JunKU7T 14052.0 33 dB CW12 wpmNorth Bend, WA1930 km (1199 miles) at 334.6 degrees*****
0344z 25 JunVE6AO 14052.0 8 dB CW11 wpmCalgary, AB2113 km (1313 miles) at 354.1 degrees******
0344z 25 JunK9IMM 14052.0 23 dB CW12 wpmMount Horeb, WI2194 km (1363 miles) at 51.3 degrees******
0344z 25 JunKO7SS-7 14052.0 17 dB CW11 wpmMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0344z 25 JunK7EG 14052.0 15 dB CW12 wpmAuburn, WA1928 km (1198 miles) at 333.7 degrees*****
0344z 25 JunVE7CC 14052.0 28 dB CW12 wpmMaple Ridge, BC2120 km (1317 miles) at 336.1 degrees******
0344z 25 JunWE9V 14052.0 22 dB CW12 wpmBristol, WI2310 km (1435 miles) at 53.7 degrees*******
0344z 25 JunVE6JY 14052.0 25 dB CW12 wpmLamont, AB2395 km (1488 miles) at 356.9 degrees*******
0344z 25 JunVE6JY 14052.0 28 dB CW12 wpmLamont, AB2395 km (1488 miles) at 356.9 degrees*******
0344z 25 JunN7TUG 14052.1 11 dB CW12 wpmSeattle, WA1973 km (1226 miles) at 333.9 degrees******
0344z 25 JunW8WWV 14052.0 13 dB CW12 wpmChesterland, OH2802 km (1741 miles) at 60 degrees********
0343z 25 JunKP2RUM 14052.0 29 dB CW12 wpmChristiansted, VI4882 km (3033 miles) at 97.8 degrees***************
0343z 25 JunK1TTT 14052.0 28 dB CW11 wpmPeru, MA3499 km (2174 miles) at 60.1 degrees**********
0343z 25 JunW2NAF 14052.0 14 dB CW12 wpmSpring Brook, PA3272 km (2033 miles) at 61.8 degrees**********
0442z 23 JunW2NAF 7052.0 12 dB CW14 wpmSpring Brook, PA3272 km (2033 miles) at 61.8 degrees**********
0412z 21 JunW6YX 14052.0 21 dB CW13 wpmStanford, CA1182 km (734 miles) at 302.2 degrees***
0412z 21 JunKO7SS 14052.0 43 dB CW13 wpmMt. Lemmon, AZ24 km (15 miles) at 40.2 degrees
0412z 21 JunKG7V 14052.0 22 dB CW14 wpmOcean Shores, WA1992 km (1237 miles) at 329.5 degrees******
0412z 21 JunW3UA 14052.0 22 dB CW14 wpmBedford, NH3632 km (2257 miles) at 59.5 degrees***********
0412z 21 JunKM3T-2 14052.0 26 dB CW14 wpmAmherst, NH3618 km (2248 miles) at 59.6 degrees***********
0412z 21 JunKO7SS-7 14052.0 18 dB CW14 wpmMt. Lemmon, AZ24 km (15 miles) at 18.6 degrees
0412z 21 JunVE7CC 14052.0 24 dB CW13 wpmMaple Ridge, BC2120 km (1317 miles) at 336.1 degrees******
0412z 21 JunTI7W 14052.0 27 dB CW14 wpmGuanacaste, Costa Rica3566 km (2216 miles) at 126.3 degrees***********
0410z 21 JunK9TM-4 14052.0 26 dB CW14 wpmSylvania, OH2824 km (1755 miles) at 94.5 degrees********
0404z 21 JunW3RGA 14052.0 7 dB CW15 wpmSunbury, PA3176 km (1974 miles) at 62.6 degrees*********
0403z 21 JunKG7V 14052.0 15 dB CW15 wpmOcean Shores, WA1992 km (1237 miles) at 329.5 degrees******
0403z 21 JunW6YX 14052.0 20 dB CW15 wpmStanford, CA1182 km (734 miles) at 302.2 degrees***
0359z 21 JunW9XG 14052.0 7 dB CW15 wpmMilan, IL2075 km (1289 miles) at 54.4 degrees******
0358z 21 JunVE6JY 14052.0 23 dB CW12 wpmLamont, AB2395 km (1488 miles) at 356.9 degrees*******

The plot below shows a historic plot of W6IWI HF CW and RTTY activity.

Also see here for a graphical representation of all RBN data. There is also a new version under development that shows similar graphs but also paths between transmit and receive sites on a map.

Search RBN for Your Station

Enter your call and click Submit to see what RBN has on you. This can be useful for testing different antennae. Transmit TEST DE CALLSIGN a few times on one antenna, switch to the other, change frequency a bit (maybe 100 Hz) and transmit again. You should see spots recorded at several locations for each antenna. Compare the reported SNR to get an idea how the different antennae perform. Click Show/Hide on the right side of the results page to enable a map with grayline showing the location of the receive sites. If your site is not shown correctly, update your location at QRZ.COM. Once logged in, select your call (right side of menu bar), then Edit your call, then Map, Grid Square and Coordinate settings. RBN uses these coordinates to place your station.

NOTE: RBN only reports CQ or TEST. It does not report every QSO. Send one of the following (I use CW and RTTY) to generate RBN spots:

Also, note that RTTY is only reported if it is at "tape speed." Hand typed RTTY is not reported.

Call Sign:

You can also use the form below to get a more detailed RBN report.

Call Sign:

More RBN Fun!

HA8TKS has an interesting set of RBN utilities. For example RBN Graph shows all stations detected by RBN in the last 15 minutes on a selected band. The graph has frequency as the X axis and time (minutes ago) as the Y axis. It shows the call of each station detected. The color tells whether the station was running CW, RTTY, BPSK, beacon, or other. You can filter to use skimmers on certain continents and filter to only show stations on certain continents. Nice view of what's going on!

Voice of America Coverage Analysis Program

VOCAP for ham radio. Originally written for the Voice of America, this predicts the best frequency between two locations at a specific time. For more info, see www.vocap.com.

Find Hams in your Neighborhood

Amateur Radio License Map maps US amateur radio operators in an area centered on a call sign, grid square, zip code, or street address. Pretty neat!

The Ham Shack

Here's an overall view of the operationg position (a rolltop desk). On the top shelf ia a lamp with a mechanical watt-hour meter. On the base to the right is a more modern version, the Kill A Watt AC power meter that measures line voltage, frequency, load current, load power, load VA, power factor, and kWH (pretty amazing). To the right of that are the two VHF/UHF handheld radios (Wouxun KG-UV-6X and a Baofeng UV-5R). The Wouxon is used as a base station with an outside antenna and a speaker/microphone. To the left of the handheld radios, you can see a couple antennae for using the handhelds portable. Behind the handhelds is a black carrying case holding the SARK-110 antenna analyzer (another truly amazing instrument). To the right is the Dentron Clipperton-L with a pair of Daiwa 501H RF wattmeters on top. The left one measures the transceiver output power, while the right one reads the amplifier output power. To the right of that is a USL CM-8E cinema booth monitor. The center channel of the CM-8E is bridged across the balanced audio line between the SEA 245 and its control head. It's used as a headphone amplifier since the SEA 245 does not have a headphone jack. In addition, the equalizer in the CM-8E is set to a narrow bandpass to act as a CW filter. On the desktop surface, starting on the left is the Chromebook laptop. To the right of the laptop is a Flesher TU-170 Teletype terminal unit with a Wave 2 handheld digital scope as an XY tuning indicator. To the right of the TU-170 is the control head for the SEA 245 HF transceiver. Below the TU-170 and SEA245 is the controller for the MFJ HAM-IV rotator that aims the Cushcraft A3S antenna. To the right (the silver box) is a switch that switches 12 VDC to the MFJ-4712 antenna switch. The bug and key are to the right. The bug is wired in parallel with the key. There are several diodes on the key so the bug and key can drive the code practice oscillator part of the MFJ 557 to provide sidetone, drive the SEA 245 and drive the CW ID input of the TU-170. On the far right is the Teletype model 15.
Dentron Clipperton-L with the cover removed. The power supply is on the left, the output tuning network on the front right, and the four 572B triodes on the right rear.
Here's a view of the SEA 245 control head. It has an RS-485 bus (called SEABUSS) that carries control information between the control head and the trnsceiver. It can also communicate with the SEA 1630 tuner, but I currently have the tuner operating stand alone. Instead of being on SEABUSS, the tuner (of course) gets the RF and PTT. It returns an open collector signal that goes low when the tuner has tuned. When transmitting, the SQL indicator (squelch) is replaced with TND indicating the tuner has tuned the antenna. Besides SEABUSS, the control head connects to the SEA 245 transceiver with a balanced audio line, the PTT line, a power on/off control (switch to ground to turn on the radio), and switched +12V. The balanced audio line is run as an analog tristate bus. When receiving, the transceiver puts audio on the bus. When transmitting, the control head puts audio on the bus. On a ship, there are typically multiple control heads connected to a single transceiver using SEABUSS.

On the right is an MFJ-557 code practice oscillator. The straight key keys both the code practice oscillator and the SEA 245 transceiver. The code practice oscillator provides "side tone." You may see a few diodes on the left side of the straight key. They provide isolation between the code practice oscillator, the TU-170 CW ID input, and the SEA 245 transceiver.

To the left of the MFJ-557 is a Vibroplex Blue Racer Deluxe. This is serial number 229386 originally owned by my father, K. E. Hallikainen (Hal). This list puts the manufacture date as 1962, which seems a bit late. Note the Round Arm Vari-Speed Accessory added to the bug. This slows it down to about 13 WPM. The bug is connected in parallel with the straight key so it also keys the code practice oscillator, the SEA 245 transceiver, and the CW ID input of the TU=170.

This is the actual SEA 245 transceiver (bottom right black box with blue Power Pole connectors). Above the SEA 245 is the SEA 1630 antenna tuner (see below for more details). To the left of the SEA 245 is the Astron SS-50M 12V, 50A power supply to power the SEA 245. Just to the right, but not shown, is a APX SUA2200 UPS that can run the station (without the Clipperton L) for an hour or two. The UPS weighs 139 pounds!

The Work Bench

Here's a veiw of the work bench. Test equipment includes a Belar FMM-2 modulation monitor. On top of that is homebrew frequency converter that converts several frequencies to the 650 kHz IF input frequency. Other equipment shown includes an audio voltmeter, oscilloscope, audio generator, distortion analyzer, and a small USB logic analyzer. There's a desktop Windows computer shown running a G4L backup. The large microphone is used for web conferences. The PTT switch on it enables the microphone and mutes the speakers making conference calls pretty easy. To the left of the computer is a CZUR book scanner I use mostly to scan broadcast equipment manuals (see https://bh.hallikainen.org ). It's a pretty amazing scanner. It takes a high resolution photograph of a pair of pages of an open book and generates PDF with background OCR. While photographing the book, it puts a few lines across the book with a red laser. It then adjusts the image to make these lines straight, flattening out the curve of the pages as they approach the binding.

Antenna Tuner

Here's a view of the Seacom SEA 1630 antenna tuner with the cover removed. It is designed to drive a wire antenna on a ship, so there is a ceramic insulator on the top to connect the wire to. Here, the tuner is driving coax (to the balun driving the inverted V). Therefore, an SO-239 was added to the side of the tuner. AWG #6 wire connects the SO-239 to the antenna tuner output at the ceramic insulator and to the ground plate in the tuner. The tuner is a pi network with capacitors to ground at the input and ouput and an inductor between the input and output. Both the inductor and capacitors consist of several binary weighted inductors or capacitors. Relays short out the inductor sections when they are not needed. Relays also ground the low side of the input and output capacitors as required. The microcontroller (in the metal box) drives the relays as appropriate to put the minimum SWR on the input. Also visible on the bottom right of the tuner is a "doorbell button." This allows the transmitter to be keyed at the tuner for checking its operation. This photo shows the tuner when it was outside As noted in the block diagram above, the tuner is now in the shack, immediately above the transceiver. It is electrically between the SEA245 and the Dentron Clipperton-L. When the amplifier is not in use, its internal bypass relay (also used in receive) connects the input to the output. The SEA 1630 then matches the antenna, as seen at this end of the transmission line, to the transceiver. When the Dentron Clipperton-L is in use, the SEA 1630 matches the transceiver to the untuned input of the Dentron Clipperton-L.

Ham Radio Resources

Ham radio resources will be collected here.

Interesting Stuff

Here's a short list of interesting radio stuff.
Broadcast History - My own online collection of broadcast equipment manuals along with LOTS of other interesting links.
California Histrical Radio Society - A great group of people collecting old broadcast equipment and history. They publish an excellent magazine that has included stuff like restoration of a mechanical television and other wonderful articles. The museum is in a 1900 telephone exchange building in Alameda CA.
Restoring a Teletype model 19 - Great series of videos on restoring a Model 19. Includes a visit to Mr. RTTY, the ultimate Teletype parts supplier.
Maritime Radio Historical Society - An operating Morse radiotelegraph shore station. The transmit site is in Bolinas CA, and the receive site and control point is in Pt. Reyes Station CA. Here are some photos from our visit in 2015. This is a wonderful project!
Remote Ham Radio - Can't put up a 200 foot tower with a four element 40 meter Yagi and 1.5 kW amplifier in your backyard? Operate one of these stations from your kitchen table with a web browser. There's an annual membership fee plus a per minute charge for use of the stations. But, this is an interesting way to get on HF from a condo with strict CC&Rs.
Reverse Beacon Network - Software defined radio receivers around the world are continuously monitoring the ham bands. These SDR receivers drive "skimmer" software that decodes CW and various digital modes. Send CQ or TEST DE CALL and see where you are received, the signal to noise ratio, and the speed (such as CW WPM). Another amazing intersection of ham radio and the Internet.
Web SDR - Software defined radio receivers around the world. In simplified form, these receivers connect an antenna to an analog to digital converter which drives an Ethernet interface (with an FPGA between) which drives a server. All tuning, filtering, and demodulation happens in the server. Multiple users use a web interface to receive the frequency of interest to that user. Each user operates their SDR software independently. It's a great way to hear what your transmitter sounds like. The web sdr can record the audio and send you the audio file. Key clicks, chirp, good speech quality? Web SDR lets you know.
Kiwi SDR - Another software defined radio running on very limited hardware. It supports 4 users and includes decoders for CW, RTTY, FAX, Loran C, Navtex, and more (see the list under Extension)
Jean Shepherd was an announcer on WOR and wrote and narrated the movie "A Christmas Story." He talked about ham radio several times on WOR. Jean Shepherd audio clips
Contra Dance - Great Fun!

Comments?

I look forward to your comments! Write me at harold@w6iwi.org.