A recent inquiry about 'BOG' antennas on the topband reflector reminded me of my own experiences with this simple yet very effective antenna. A 'BOG' or 'Beverage On Ground' seems to come in many varieties and is usually, out of necessity, shorter than a 'real' beverage.
In many instances, BOGs are as simple as running a wire out on the ground as long and as straight as practical. Not always, but usually, the BOG is fed by a small homemade balun to isolate and match the impedance to a 50 ohm feedline. Most real Beverages are terminated at the far end with a resistor to ground, while for BOG builders, some use it and some don't.
My own experience with a BOG, or as close as I could come to one, was an extension of my 160m half-sloper. The topband half-sloper was quite normal, being about 132' long and fed at the top of its supporting metal tower with 50 ohm coax ... the hot-side of the coax going to the wire and the shield going to the metal tower.
One afternoon I wondered how the antenna would work lower in frequency, in the NDB band below the broadcast band, if I were to extend the sloping 132' element further. I added another length of wire to the lower end and proceeded to run the wire along the ground on the bankside above the beach. I was able to run out another 500' approximately, in a straight line to the east, before running out of beach. I left the far end unterminated and waited for darkness to to have a listen.
The first thing I noticed when tuning the NDB band was how quiet it sounded. There seemed to be almost no noise, man-made or nature-made. Disconnecting the antenna showed a small drop in what little noise there was, indicating that sensitivity levels were still being determined by skynoise ... a good thing.
What amazed me however, was that signals just popped-up everywhere and although not as strong as on my normal NDB antenna (a loop at the time), they were much better copy since there was virtually no noise. The BOG produced a significant improvement in my SNR on all signals. It had been several months since I had logged any new beacons on the NDB band but over the next three weeks I was able to put 65 new catches in the log ... all previously unheard! Switching between the loop and the BOG almost always produced no copy at all on the new signals, compared to an easily copied one on the BOG.
My experience was very similar to that shown in these videos by VO1HP ... with solid signals well out of the low noise background and no sign of atmospheric noise to mask them.
It is clearly evident that the BOG delivers a much better SNR than the comparison loop and is the reason so many topbanders use a separate antenna for receiving. The next video compares the BOG with a 160m 'Inverted-L', a very popular antenna on topband.
BOGs need not be really long and good results can be had with just 200' of wire. Many BOG users employ a simple preamp to boost the low level of signal but often the switchable 'preamp' built into a receiver or transceiver will be enough to overcome the low gain of shorter wires.
I've often thought that if I had a lot of acreage, the ideal receiving system for MF and LF work would be a centrally located radio shack with long Beverage wires fed-out in various directions ... like the spokes of a wheel. Having the ability to directionally switch antennas would produce 'beam-like' capabilities on LF.
There is a ton of web information available on the BOG and the Beverage should you want to give this simple antenna a try and have a narrow strip of space where one might be laid out without causing a problem.
A very comprehensive source of BOG and Beverage information can be found on WØBTU's Beverage Receiving Antennas page here.
A nice compilation of Beverage / BOG exchanges from the Topband Reflector may be found on N1EU's Beverage Antenna Tips page here.
In addition, N1EU has a useful page of discussion about transformers used in these antennas.
PA5MW offers a colorful description of his own BOG experience here.
Bruce, K1FZ has a nice BOG 'hint's' page here and also passed this advise to the original BOG inquiry:
A BOG can do a good job unterminated. If too long they self terminate. Depends upon the soil as to length.
The biggest mistake is making the BOG antenna too long. Try not to go
over 200 feet for 160 meters. Longer will work in some locations
soil like desert, sand, other non/ partial conducting types.
Its been a few years since my last experience with a BOG but I may run one out again for the DX season, now that most of my neighbours have left the island for the winter.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].
Here is this week’s space weather and geophysical report, issued 2016 Sep 26 0103 UTC.
Highlights of Solar and Geomagnetic Activity 19 – 25 September 2016
Solar activity reached low levels this period due to isolated C-class flare activity. Region 2595 (N11, L=099, class/area=Dao/120 on 20 Sep) was the most productive region this period. In addition to multiple low-level C-class flares Region 2595 produced the largest event of the period, a C5 flare at 22/0547 UTC. Region 2597 (S13, L=349, class/area=Dsc/120 on 24 Sep) developed late in the week and produced an isolated C1 flare at 25/1914 UTC in addition to numerous B-class flares. No Earth-directed coronal mass ejections were observed this period.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 21 Sep, moderate levels on 22-23 Sep, and was at normal levels throughout the remainder of the period.
Geomagnetic field activity reached G1 (Minor) geomagnetic storm levels on 20 Sep with active levels observed on 21 Sep in response to the influence of a negative polarity coronal hole high speed stream. G1 (Minor) storm levels were observed again on 25 Sep due to prolonged periods of southward interplanetary magnetic field orientation. Quiet conditions were observed on 22-24 Sep and quiet to unsettled levels were observed on 19 Sep under a background solar wind environment.
Forecast of Solar and Geomagnetic Activity 26 September – 22 October 2016
Solar activity is expected to be at very low levels throughout the period with a chance for C-class flare activity.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be very high on 02 Oct with high levels expected on 29 Sep-01 Oct, 03-11 Oct, and 18 Oct following periods of an enhanced solar wind environment associated with coronal hole high speed stream influence. Normal and normal to moderate flux levels are expected throughout the remainder of the period.
Geomagnetic field activity is likely to reach G2 (Moderate) geomagnetic storm levels on 28-30 Sep and G1 (Minor) storm levels on 26 Sep, 01-02 Oct, and 17 Oct due to the anticipated influence of multiple, recurrent coronal hole high speed solar wind streams. Active conditions are expected on 27 Sep, 03 Oct, and 18 Oct with generally quiet and quiet to unsettled conditions likely throughout the remainder of the period.
Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/
Live Aurora mapping is at http://aurora.sunspotwatch.com/
Get the space weather and radio propagation self-study course, today. Visit http://nw7us.us/swc for the latest sale and for more information!
Check out the stunning view of our Sun in action, as seen during the last five years with the Solar Dynamics Observatory (SDO): https://www.youtube.com/watch?v=zXN-MdoGM9g
We’re on Facebook: http://NW7US.us/swhfr
Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Contact him at [email protected].
Some exciting news wandered into my inbox this past week concerning a handheld radio driven by the Android operating system. The RFinder H1 is an FM plus DMR radio to be released at the end of this month. Click to enlarge the photo to the left to get a better view. I had proposed a similar concept back in 2012: The Android HT, so this radio immediately grabbed my attention.
Details are still a bit thin on the RFinder H1 (pronounced “Ar Finder H 1”) but this video gives you a glimpse of its operation. The 70cm band radio apparently also supports GSM and 4G/LTE mobile phone formats.
There are a few other YouTube videos available, one of which emphasizes the easy programming of the radio using the RFinder online repeater directory. This makes perfect sense and is a great example of the power of a connected device. This feature would be very handy for programming up FM repeaters on the fly and outstanding for dealing with the complexity of DMR settings.
The RFinder H1 includes DMR capability, something I wasn’t thinking of back in 2012. That also makes perfect sense…embracing the growing amateur radio format that is based on industry standards.
Very cool development. What do you think?
73, Bob K0NR
Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].
High-speed imagery downlink making use of SSDV
In our payload, we use SSDV to compress images captured by a PiCam, then transmit them via 70cm FSK at 115kbaud.
ARRL 2016 Simulated Emergency Test is October 1-2
Every local ARES team and/or ARRL Section will come up with their own scenarios and work with served agencies and partner organizations during the SET.
End-Fed antenna revisited
I really like the simplicity of this antenna for many aspects: fast to deploy, works on many bands, no antenna to tune…
How to undertake a SOTA Activation – Step by step guide
It covers the set-up, spotting, operating procedure and tips and tricks I’ve picked up over the last few years.
Adventures in Ham Radio
In a nutshell, IRLP links repeaters and individual nodes, like mine, with others via the Internet.
A single lever paddle
The only paddle I have is a Bencher, which is a bit too heavy and cumbersome to carry in my backpack for a portable set-up.
NPOTA: Photos from weekend “two-fer” activation
My family visits national parks regularly, so it’s easy for me to pack a small radio, do a quick NPOTA activation all while incorporating non-radio activities that the family loves.
The SWLing Post
VDSL interference: A Ham operator’s nightmare
Unfortenately still sometimes we lost the complete DSL connection and in that case we had to wait for 5 minutes to get TV, internet and phone back online.
Radio club coordinates energency response during cycling event
Huntsville Amateur Radio Club volunteers were instrumental in coordinating the communications amongst event organizers and volunteers, emergency personnel.
AT&T’s New “AirGig” Not Your Father’s BPL
ARRL’s earlier anti-BPL campaign, and market forces, eventually led to the demise of the prior BPL initiative.
AT&T Labs’ Project AirGig nears first field trials
AirGig could one day deliver low-cost, multi-gigabit wireless internet speeds using power lines.
Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.
I’ve bought a few odds and sods from Richard, G3CWI at Sotabeams in the past. Stuff like a super cheap End Fed Half Wave tuner for my MT5B that took about 30 minutes to make, a SB270 dual band 2m and 70cm yagi which is my favoured UKAC antenna and things like antenna winders. But, I ventured into DSP and bought a Laserbeam CW DSP filter on a whim at the NARSA Norbreck rally and to my shame haven’t really used it too much. The complaint was that I didn’t get round to boxing it up. Now all that has changed. There’s a kit! not just a box but an amplifier as well.
Richard now sells plenty of different types of filter from single SSB and CW types as well as a variable version and even one for the ft817 (next stop I think). He also sells a neat little box and audio amplifier kit. Something that was clearly missing from the original line up. I paid my money and a few days later mine arrived. Some downloaded instructions from the website were used and within 30 minutes the very good quality PCB was populated and they enclosure being prepared. Here is a small niggle, the case is an aluminium extruded type that follows the Hammond 1455 style but is an alternative that is no doubt cheaper. The end pieces are laser cut and engraved acrylic that don’t quite fit flush with the holes and the self tapping screws are driving int thick aluminium and as such are prone to slipping and potentially able to fowl the front panel. There is a very minor issue with fit and in my case the audio jacks sit ever so slightly too far out and as such force the thin acrylic to bow. Lesson learnt is that fit those parts more conservatively to avoid the bowing. That being said its a small gripe.
Powering up is straightforward. Anything from 5-15v works and so my standard 12v ‘checking stuff’ battery powered it up first time and I soon noticed that the audio was quite loud with my headphones. The front panel has a volume control and a handy LED reminder if you drive it too much. The sweet spot is just below the level LED ‘light up’. A second LED shows the incoming signal and a wide / narrow switch chooses between wide and narrow settings of course. The website shows lots of graphs and technical guff but using it is clearly what I’m after and it certainly doesn’t disappoint. The ability to remove unwanted signals is just brilliant. For such a cheap unit I can’t think why I didn’t get my backside in gear earlier.
The minor mechanical niggle aside, I would recommend this as a simple and effective filter. It is cheap, simple, razor sharp and a really useful add on. Long may it carry on filtering!
Alex Hill, G7KSE, is a regular contributor to AmateurRadio.com and writes from Cumbria, UK. Contact him at [email protected].
The smell of autumn is in the air today. It’s beautiful and warm. Judy and I take a bicycle ride along the Pemigewasset River. I work Africa, Ukraine, Croatia and Spain.
We ride down along Needle Shop Brook and turn north along the river. There are fallen apples and brown leaves on the road. It feels and smells like fall. But it’s warm and still. A perfect day for a bike ride.
We ride about a half mile north and I see what I think is a piece of metal across the trail. I swerve quickly to avoid it, and realize it’s a snake! It slithers away into the grass. It’s a Northern Water Snake soaking up the warm, fall sunshine.
We ride perhaps 3 miles and I start looking for a place to set up the KX3. There is a sunny field to the west with some large maple trees nearby. Judy goes into the field and I throw a 30 foot wire over the branch of a huge maple.
I start out on 20 meters at the low end of the band. EO25U is calling CQ. We exchange quick 599s. This is Ukraine… a special event celebrating 25 years of independence. I tune up the band and quickly work AN400R… another special event… this time in Spain celebrating the life of Cervantes, the famous Spanish author of Don Quixote.
The photo below is my view while operating.
I switch to 17 meters. It’s active and right away I work 9A50CMB. This is the MARJAN Radio Club call in Croatia. Miki gives me a 559, and I tune up the band a little. Here is TZ4AM working stations. He answers me on the first call and gives me a 559. I didn’t know this station is in Mali, central Africa. I find out later when I look it up at home. Wow… the first time I’ve actually worked Timbuktu!
Now I pack up and head south to where we left the car.
These days are way too short. In just a few weeks New Hampshire Fish and Game will release pheasant in this area for hunters. Not an ideal spot for bike rides or radio.
Jim Cluett, W1PID, is a regular contributor to AmateurRadio.com and writes from New Hampshire, USA. Contact him at [email protected].
|'OO'- - 391 kHz Oshawa, ON|
This coming weekend will see another CLE challenge, this time in the 15 kHz slice from 385.0 - 399.9 kHz.
A 'CLE' is a 'Co-ordinated Listening Event', as NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.
A nice challenge in this one is to hear the Oshawa, Ontario NDB, 'OO' on 391 kHz. This one runs at just 7 1/2 watts output and gets out amazingly well having been logged here last year. It has even been heard in Europe!
From CLE organizer Brian Keyte, G3SIA, comes the usual 'heads-up':
Our 211th Listening Event is only a few days away.
The Northern Hemisphere summertime storms have subsided, the equinox
will have passed when the CLE starts and we can all hope for some good
Whether you are a keen propagation watcher or just a take-what-comes
listener (like me), please join in.
Days: Friday 23 September - Monday 26 September
Times: Start and end at midday LOCAL TIME
Range: 385.0 - 399.9 kHz
Please log all the NDBs you can identify that are listed in the range
(it includes 385 kHz but not 400 kHz) plus any UNIDs that you find there.
We last used this frequency range for CLE194 in May 2014.
Please send your CLE log to the List in a plain text email if possible
(not in an attachment) with 'CLE211' at the start of its title.
Show on each log line:
# The date (e.g. 2016-09-24, etc., or just 24) and UTC.
(the date changes at 00:00 UTC)
# kHz (the nominal published frequency, if known)
# The Call Ident.
Show those main items FIRST - other optional details such as Location
and Distance go LATER in the same line.
As always, tell us your own location and brief details of the equipment
that you were using during the weekend.
Good listening - enjoy the CLE
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE co-ordinator)
(If you wish you could use any one remote receiver for your loggings,
stating the location and owner - with their permission if required.
A remote listener may NOT also use another receiver, local or remote,
to make further loggings for the same CLE).
These listening events serve several purposes. They:
- determine, worldwide, which beacons are actually in service and on-the-air so the online database can be kept up-to-date
- determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range
- will indicate the state of propagation conditions at the various participant locations
- will give you an indication of how well your LF/MF receiving system is working
- give participants a fun yet challenging activity to keep their listening skills honed
Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event. If you are a member of the ndblist Group, results will also be e-mailed and posted there.
The very active Yahoo ndblist Group is a great place to learn more about the 'Art of NDB DXing' or to meet other listeners in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.
If you are contemplating getting started on 630m, listening for NDBs is an excellent way to test out your receive capabilities as there are several NDBs located near this part of the spectrum.
You need not be an ndblist member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers. 'First-time' logs are always VERY welcome!
Reports may be sent to the ndblist or e-mailed to either myself or CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above.
Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].