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Antenna Analyzers

You Can Hack

By Dan Romanchik, KB6NU

I'm a nut for antenna analyzers. I think that they

are one of the most useful things a ham can own. I’ve often wondered why there aren’t more DIY antenna analyzer projects, though. Perhaps it’s because designing measurement circuits isn’t easy. An antenna analyzer has to have a signal source as well. Even so, an antenna analyzer doesn't need a whole lot of accuracy to be useful, so you would think that more builders/hackers would tackle a project like this. I don’t know of one antenna analyzer kit on the market. The VK5JST Antenna Analyser Kit (http://www.ahars.com.au/about/kits/)

costs about $110 USD. I actually purchased this kit a year or so ago, and it looks like a great unit. The unit seems well-designed, and it comes with a plastic case, unlike many projects these days, but I haven’t yet gotten around to building it. I've also recently found out about an Arduino-based antenna analyzer project (http://hackaday.com/2015/08/06/40-antenna-analyzer-with-arduino-and-ad9850/). It uses an AD9850 module as the signal source. The approximate cost for all the parts is about $40, and you can experiment with the code, if you like. If you have the time and inclination, this project might be worth taking a hack at. [[NOTE

Analyzer antenna analyzer project from Australia is the VK3YY antenna analyzer (or "analyser" as they spell it there). It uses an Arduino Nano. The interesting thing about the blog post in which VK3YY describes the project (https://vk3yy.wordpress.com/2014/09/29/antenna-

analyser-project/) is that you can follow his design and experimentation process. Yet another analyzer: While I’m talking about antenna analyzers, let me mention another one that I’ve just found out about: the IW2NDH Antenna Analyzer (http://www.iw2ndh.com/). This antenna analyzer isn't a kit, but at $175 seems to be a good deal. This unit has frequency coverage of 2 – 160 MHz, and can be used as an antenna analyzer, signal generator, and a scalar network analyzer. Apparently, this started out as an Arduino project. As Maximo, EA1DDO, pointed out on the radioartisan Yahoo Group, there is source code for this project on GitHub (https://gist.github.com/jackdev23/7876502), and a schematic is available on the Union de Radioaficionados Espanoles (URE) website (http://www.ure.es/media/kunena/attachments/2420/Schematic.jpg). ==================================== When not writing about antenna analyzers, Dan, KB6NU, actually builds an antenna now and then. You can often find him on the HF bands (mostly 40m and 30m), working CW. His #1-rated amateur radio blog can be found at KB6NU.Com, and you can e-mail questions, comments, or complaints to: cwgeek@kb6nu.com.

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12V Power Distribution Strip, W1ZE Style

By J.Bruce Randall, W1ZE

As most of you know I have a substantial

selection of Ham Radio equipment in the old W1ZE shack. Most of the equipment, accept for my old trusty IC-736 and my Ameritron AL-572 amplifier, run off a 35-Amp 12 volt switching supply with deep-cycle storage battery backup. To feed all the equipment I have a spaghetti maze of red-black 12 volt twin-lead running from the various units to the power supply via an old 12 volt 5 terminal power strip I made up years ago from parts obtained at Radio Shack. With the limited terminals on the strip and on the power supply I didn’t have enough dedicated terminals for each piece of equipment, so I had to piggy-back several leads on one terminal set inducing potential connection problems. In the July, 2015 issue of QST on page 67 there was an article by Steve St. Andréa, AG1YK on an nifty 12 volt power distribution strip he made up from two power distribution load panel grounding bars and a hand full of common nylon and steel (or brass) fasteners. I said to myself, “self, you old son-na-ma-gun, you could build something like that.” So off to the hardware emporium (this time Lowe’s) and purchased two 18-terminal HomeLine PK18GTA grounding bus bars and some 8-32 nylon screws and nuts and four 3/8-inch long nylon sleeves to be used as terminal strip standoffs.

Some time ago I started cutting chunks out of an old nylon ¼” thick kitchen cutting board as insulation material for various antenna projects and thought that material would make a good

non-conductive base platform for the two bus-bar terminal strips. From that old cutting board I cut a 7” x 2-3/4” rectangle, then drilled and counter sunk four small mounting holes to facilitate four 8-32 metal fasteners and nylon sleeve standoffs to mount the bus bars to. Before I assembled the distribution panel I removed all the set screws from the two grounding strips them panted one strip “RED” and the other strip “BLACK” so as to remind me

which strip was positive(+) and which was

negative(-). After the paint dried I started assembly. I used two 1-1/2” long 8-32 nylon screws to merry the two bus bar strips in parallel. Then isolated the two strips from each other by placing a 8-32 nylon nut on the nylon screw between the two strips to maintain adequate separation. The four 3/8” nylon sleeves were used as strip mounting standoffs/spacers allowed easier screwdriver access to the set screws when connecting and disconnecting power leads to the strip.

Finished 12VDC Distribution Terminal Strip

In my semiconductor storage box I found a 12VDC red LED I had purchased years ago and did not use. I installed it to the end terminal point with the + lead to the red strip and the – lead to the black strip giving me a power indication light. A regular LED in series with a 1K resistor would do just as well. As shown in the QST article you can make up Anderson

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Powerpole adapters and mount them into the strip for easy connection of equipment power leads that require a Powerpole connections. My total investment in the project was less that $20. The big ticket items were the two grounding strips that were a little less than $8.00 each. You may be able to find them online at a lower price. In the positive (red) power lead that runs from the power supply to the new power distribution strips I installed a 30-Amp fuse and fuse holder for added protection against distribution strip overload or the infamous, ‘OOPS’, I forgot to turn off the power supply ‘ problem when installing or removing power leads. You can find commercial ready made 12-volt power strips at Ham stores and on line but not for twenty bucks. Jetstream has the 6 terminal JTDC6 strip for $30.00 and MFJ has several types from $44 to $115, Yes, they may have a few more bells and whistles but they are still just a power strip in a box. My power strip supplies four 100-watt HF/VHF multi-mode transceivers, two VHF/UHF 50-watt FM transceivers plus other relay control devices and accessories. There does not seem to be any voltage drop (power loss) in the homebrew husky distribution terminal strip. Try it, you may like it. 73, Bruce/W1ZE

NEWS FROM NEWINGTON

Outcome for 5 MHz at WRC-15

Remains in Limbo ARL ARLB026

With the deadline to submit proposals to World Radiocommunication Conference 2015 http://www.itu.int/en/ITU-

R/conferences/wrc/2015/Pages/defau

lt.aspx

now less than 2 months away, it's still unclear how at least one agenda item of importance to the Amateur Radio community will fare. That is agenda item 1.4, which calls on the delegates to consider a secondary Amateur Radio allocation at 5 MHz (60 meters). In the US and in most other countries that have privileges there, ham radio has a set of fixed channels at 5 MHz not necessarily the same from one country to the next, although most are common. As ARRL Chief Technology Officer Brennan Price, N4QX, explained last spring following the second Conference Preparatory Meeting (CPM), the agenda item 1.4 proposals at the CPM were "all over the map - ranging from no change to an expansive allocation of 5275-5450 kHz, with explicit suggestions of 15 kHz and 100 kHz in between, and a few methods with details to be filled in later." As Price summarized at the time, "[T]here is a wide divergence of opinion, and no certainty as to the outcome." In his July 2015 report to International Amateur Radio Union Region 3 Conference to be held this October in Indonesia, ARRL CEO David Sumner, K1ZZ, said that while the US is "generally supportive" of the Amateur Radio and Amateur-Satellite services at WRCs and in other International Telecommunication Union (ITU) venues, "it has been difficult to gain support from the federal government side for agenda item 1.4." The ARRL is a member of IARU Region 3 to represent the interests of FCC-licensed radio amateurs residing in Guam; the Northern Marianas; American Samoa; Baker, Howland, Jarvis, and Wake islands; Palmyra Atoll, and Kingman Reef. When he submitted the report to IARU R3 in July, Sumner had said that the best ARRL could hope for in the US position was a 25 kHz secondary allocation at 5 MHz, "and only then if this becomes the CITEL Inter-American Proposal (IAP)," he explained. CITEL completed its work earlier this month and will put forward an IAP for a 175 kHz secondary allocation at 5275-5450 kHz, with support by up to a dozen countries. That's not a

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proposal the US or Canada could support, however. Sumner noted that as of now, only one formal proposal for agenda item 1.4 has been submitted, and it calls for no change at 5250-5450 kHz. It came from the Regional Commonwealth in the Field of Communications (RCC), the regional telecommunications organization made up primarily of the former Commonwealth of Independent States countries of which Russia is the largest. Other regional telecommunication organizations still have not submitted formal proposals. Sumner said this week that it's not possible to predict what might happen at the European Conference of Postal and Telecommunications Administrations (CEPT) meeting in a few weeks. CEPT is the umbrella organization for 48 European nations. "We appreciate the strong support from so many Latin American and Caribbean administrations and remain hopeful that a favorable consensus can be reached in Geneva in November," Sumner said. In Europe, Hungary's telecommunications regulator NMHH has begun issuing temporary permits to radio amateurs there to operate in the band 5350-5450 MHz on a secondary basis for research. The permits are valid for 3 months, and holders may reapply after that. According to the Dutch Amateur Radio Association (VERON), telecommunication regulator Agents chap Telecom is expected in September to release 5350-5450 kHz to radio amateurs on a secondary basis for all operating modes. The primary users of the band, which include the Netherlands military, already have agreed to the allocation. Several other European countries already have 60 meter allocations. WRC-15 will take place November 2-27 in Geneva.

Launch Date Set for AMSAT Fox-1A ARLS013

AMSAT Vice President of Engineering Jerry Buxton, N0JY, has announced that the Fox-1A

CubeSat will launch on October 8 from California. It initially had been set to launch in August. Fox-1A will include an FM transponder with an uplink frequency of 435.180 MHz, and a downlink frequency of 145.980 MHz. The first phase of the Fox series 1-Unit Cube Sats will allow simple ground stations using hand-held transceivers and simple dual-band antennas to make contacts. The Fox-1 CubeSats also will be able to transmit continuous telemetry during normal transponder operation. The satellites will feature 200 bps telemetry in the audio spectrum below 300 Hz. ----------------------------------------------------------- Editors note: Get the up-link and down-link frequencies programmed into your dual-band FM transceiver or HT and get ready for some satellite communications fun through the FOX-1A cube sat.

Technician Class

License Study Guide

(FREE)

Dan Romanchik, KB6NU of Ann Arbor, MI is a frequent contributor to this newsletter with his advice and opinion articles. Dan is also a strong proponent of increasing the ranks of Amateur Radio community, something we all want. Dan has produced a study guide for the entry level Technician Class license that appears to be well written, gets the point across and should be a big help to a Ham want-a-bee

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interested in getting his or her first ticket and join our great hobby. The study guide is in PDF format and can be downloaded from the following DX Zone website for FREE:

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=31302

or http://www.kb6nu.com/tech-manual-

feedback/ If you know of someone interested in studying for their Technician Class license, Tell them to download the study guide or as a gift to them, email them the PDF document so they can get started. Don also publishes a study guide for the General Class license. Check out:

http://www.kb6nu.com/study-guides/

Coax Cable and Line Loss

Calculator Developed by Juan Veranes, CO8TW

When planning an antenna project everyone researches things like heights above ground, potential gain, front to back ratio, etc.. However, one thing sometimes forgotten to add to the mix is transmission line loss. If your antenna is fed with 400 to 600 ohm window line/ladder line, losses are not a big factor, It is a different story when it comes to unbalanced coax, RG-58, RG-213, RG-8, the LMR series of coax, etc.. Say for an example you spent a hundred plus bucks for a nice new shiny three element aluminum six meter yagi and got it up on a pole on your roof. You ran about 100-feet of RG-8X low-loss coax down to your 1600 dollar multi-band transceiver. You checked the SWR and it looked damn good, 1.25:1 or less. But, did you know that not all that 100-watts of RF was making it to your antenna? In fact, only about 60-watts was making it to the antenna, about a 2.2db loss in power to the antenna and close to that in received signal loss. You put out all those bucks for just a 60-watts signal. If that were a two meter antenna your loss would be over 4-db, over half your power. You can live with it,

but if you would have spent a few more bucks for 100-feet of say LMR-400 your power loss at 50 MHz would be only 0.8db and the power to the antenna would be more like 82-watts. There is a website that provides a nifty coax loss calculator developed by Juan Veranes, CO8TW in Santiago de Cuba that works slick. Just enter a few known factors into the online calculator and within less than a second your coax loss is calculated. Check it out because it may help you now or in the future. http://www.qsl.net/co8tw/Coax_Calculator.htm

Windsor Ham-fest, a fun event

Windsor, ME: The sun was out at 8:00am on Saturday, September 12th the gates opened at the old Windsor Fairgrounds for the start of the Augusta Amateur Radio Association’s 2015 Windsor Ham-fest. It appeared that the attendance was up a bit from the past several years. There was a good sized contingent of MARA folks there too. Most were there to help with the Associations sales of donated items, thanks to the generosity of Sid Corderman, K2CML. Sales were pretty good and a few more

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dollars were added to the Associations piggy bank. DR Steve Kercel, AA4AK used the sales tent to do his ARRL QSL card verification for DXCC and other League operating awards. Right off the bat Tom Donohue, W1QU of Ellsworth handed Steve a big batch of DX QSL cards. Steve with eyes of a tax accountant started the verification process. After some time Steve finished, put his Okie-Dokie to the DXCC form and Tom looked very pleased with the outcome.

It appeared that everyone had a very good time pawing through all the goodies offered for sale by the vendors and there were numerous eyeball QSO going on all over the place. A big “THANKS” goes out to the AARA from the MARA for providing the ham community here in Maine a place to gather and have some fun on a sunny day.

A considerate Operators Frequency Guide

The following ARRL website provides a Ham Band frequency chart than can help to keep the new and old Amateur Radio Operators from being frowned at by your fellow hams. If you follow the recommended mode vs frequency chart you too will be an A-1 operator.

http://www.arrl.org/files/file/conop.pdf