KL7UW

SIX METER PAGE



ALASKA 6M BEACONS: KL7KY -- 50.063.3 MHz - 25w OMNI -- Wasilla, BP51 KL7J's HF Propagation page. SOLAR FLUX: WM7D Solar Resource Page: http://www.wm7d.net/hamradio/solar/index.shtml Dominion Radio Astrophysical Observatory Geomagnetic Index, Kp AURORAL ACTIVITY: Aurora from NOAA POES Satellite: Ovation Aurora Forecast
Aug. 25, 2016 Update: Completed wiring of control panel to HP 50v switching PS and fabrication of fan assembly for the Harris amp. Initial testing results using Bird43 meter 5A, 50A*, and 1000A elements; antenna as load: In Rx mode with voltage applied to the Harris amp: V = 51.2 and current under 1 amp with fans running. Red LED indicator is on steady. Mode RF drive V I Power out Indicator Tx 0w 49v 12a 0w Green Tx 1w 49v 19a 100w Green Tx 2w 49v 24a 190w Green Tx 3w NA 28a 250w Green Tx 4w NA 31a 340w Green Tx 5w NA 33a 390w Green Tx 5w* NA 36a 480w Green Tx 7w* NA 43a 650w Green Tx 8w* NA 44a 700w Green Tx 9w* NA 48a 850w Green Tx 10w* 48.6v 49a** 900w Green ** HP PS full output is 50 amps. K3 driving Yaesu FL6020 linear amp at 0.7w for 5w output; 1.8w for 10w output. * Bird 50A shows 0.5w lower reading than 5A element for 5w RF level. Harmonic filter under construction. I built the harmonic filter from QST article: "A High Performance, Low Cost 1.8 to 54 MHz Low Pass Filter" (Bill Jones-K8CU, Nov. 2002 pp 34-38). I'm hoping to get permission to link to the article or obtain reprint file. I enclosed my filter in a 6-3/4 by 4-3/4 by 2 inch diecast aluminum Hammond Box and used high quality Teflon N connectors. The five pole filter is constructed with two capacitors made from 0.032 inch brass plate insulated by 1/32 inch Telfon sheet. Three coils of 1/8 inch copper tubing are in series between connectors with two capacitors to ground. A small adjustable capacitor of brass plate and copper flashing permits tuning for best SWR (1.15) and injection loss is almost not measurable. I had to short one turn of L3 to bring SWR minimum up from 35 MHz to 51 MHz. 2nd Harmonic rejection is -55 dB at 100.400 MHz (98-MHz is frequency of the max reject >60 dB). Measurements were done using a HP signal generator at 0dBm and a HP141T/8554L Spectrum Analyzer. W6PQL Dual Directional Coupler for 50-MHz for 1000w was purchased and installed in 2.75x2.75x2.00 inch aluminum chassis with N-connectors for RF and ferrite beads and 1000pF feedthru caps for coupling out the Fwd and Rev dc voltages. These will be fed to a surplus SWR Panel meter and logic made by Telewave. Adjustable pots will be used for setting appropriate levels to the meter from the directional coupler. Logic board has shutdown relays for excess reverse power plus audible alarm and LED indicators. This will replace using the Bird43 power meter for monitoring RF output of the Harris amplifier. To get a reading on the Telewave meter the 27-dB pi-attenuator was lowered to 24-dB which provides 1.7 vdc driving the meter to display 90w for 900w. On reflected power 100w displays as 200w with 0.5vdc from the directional meter. DC output from directional coupler is passed thru two variable resistors to adjust the display and providing fixed load to the detectors (10K and 3.2K, respectively). Jan. 2016 Update: Purchased Elecraft HF/6m Linear Amplifier and sold Mirage A1015G amplifier. Dec. 2013 Update: Rohn-45G tower installation (photos): December 12th the antenna was finally installed. Initial testing shows excellent SWR from 50.110 to 50.260 MHz.





July 2013 Update: One of the 3-element 6m yagis was installed on tower#2 side-mounted at the 22-foot level and pointed in a fixed direction of az=130 to cover SE Alaska and the West Coast of the US. This antenna will be used for monitoring for openings on 6m and for working stations to the south during local nets, photos: June 2013 Update: The 6-element yagi sustained damage last winter breaking two center insulators. It has been taken down along with the push-up mast. A 20-foot Rohn-45 tower will be installed to replace the mast and be fitted with a Ham-IV rotator. June 2011 Update: The 6-element 6m yagi installed, June 21, 2011. April 2011 Update: Thanks to a kind donation of a 12w/1100w sspa for 6m, I am proceeding with installation of 6m EME. For a thorough explanation of conversion of Harris Platinum TV amplifiers to 6m operation go to http://www.bigskyspaces.com/w7gj/HarrisAmps.htm Thanks for cash contributions from Kerry, G8VR and Fred, G4BWP which went toward acquiring 75-feet of LMR-600 feedline and the antenna. I've ordered a HP 226519-001 50-volt, 50-amp switching power supply from e-bay for $30.98 (including shipping). KL7FZ has several 44-MHz KLM 7LB log-periodic cell 7-element yagis that can be moved up to 50.2 MHz. I ordered one from him (they were for a state-run meteor scatter network and he has several new-in-box antennas). I have two sections of 7/8 Heliax cable to provide a 90-foot feedline but will need about 50-foot LMR-600 to complete the run. Initially, I am going to mount the 30-foot long yagi on a guyed Rohn push-up mast at about 22-feet without a rotator. I will provide cords off both ends of the 30-foot boom for steering. The antenna will be horizontal and fixed elevation on the horizon. I will try operation with the preamp in the shack but the TR relay and preamp may get moved to the antenna. I have decided to modify the antenna to a six-element yagi design offered by Mike, K6MYC. This will eliminate one of the log-periodic driven elements Mike has dubbed the design as 6M6UW. The yagi will exhibit 13.1 dBi gain with 21-dB F/B ratio on a 30-foot boom. This is close to the performance of the M2 6M7JHV. This will also be useful for 6m meteor scatter! Summer 2017 I will add a second yagi and elevation of the array for 16 dBi total gain. Minor modification to the 6m control diagram (deleted PA shutdown ckt).





2010 Update I have a new Elecraft K3/10 which runs 8w on 6m. An ARR P50VDG 6m Preamp was added for improved Receiving on 6m. July 2010 I bought a Mirage A1015G amplifier which outputs 125w with drive from the K3/10. The lower 6m yagi is not loading so unusable and will be removed. The upper 6m yagi works well. November 25, 2008 Update HF triband yagi, two stacked 6m yagis*, 222 and 432 antennas installed on the extended 50-foot tower. All antennas were installed with the tower layed over to ground, and later raised with a boom-truck. Coax cables were run to the 6m yagis, HF yagi, and 432 yagi. Later plans are to run 7/8-inch Heliax to the 222 and 432 antennas (selected with a coax relay). *Note: the 6m yagis were removed in summer 2012. January 14, 2007 Update We decided to temporarly install a 6m yagi, 432 yagi and two 222 yagis on 30-foot of tower. This will be increased to 50-feet with the HF yagi and second 6m yagi being installed.
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