Category Archives: Receiver
I would venture to say you can’t do better than hearing it from the inventor himself!
Here is an excellent YouTube video from RimstarOrg that breaks down the concept of how crystal radios actually DO their magic! Yes, MAGIC. Radio signals are all around us 24 hours a day. Invisible! You can’t really touch them. You can’t smell them. You can’t hear them without assistance. We don’t really feel them bombarding us. We don’t sense those signals without some mechanical help… but they strike us with many different frequencies constantly… so let’s explore the range of frequencies we can decipher with a homemade crystal radio set!
10 Meter Ham Radio Beacons (28 MHz) help us know where propagation is working in our favor for communicating around the world. OfficialSWLChannel provides another excellent video on how to take advantage of these beacons!
K7AGE has a superb series of ham radio videos and I have learned a lot from them. Subscribe to his YouTube Channel for information on TONS of topics about amateur radio!
These are very handy for all sorts of your 12 volt ham radio projects!
Will be looking for these at the next hamfest!
How GPS Works
Basic APRS – An Introduction
(Click link above for the ARRL APRS webpage explaining APRS)
“Official U.S. Government information about the Global Positioning System (GPS) and related topics”
GPS Modernization Video
GPS is getting an $8-billion upgrade
“Without it, ATMs would stop spitting out cash, Wall Street could blunder billions of dollars in stock trades and clueless drivers would get lost.”
New Satellites Could Make GPS Harder to Jam
“Without GPS, drones can’t fly, communications networks can’t function, and you don’t have a chance of figuring out how to get to your Aunt Sadie’s place in New Jersey. And right now, GPS is highly vulnerable because its weak signals are coming from an aging constellation of satellites.”
How GPS Receivers Work
“Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky.”
Check out the Air Force Collaboratory:
How Collaboration Leads To Great Ideas
How Robots Help Search And Rescue Teams
Voyager 1: Where To Next?
Did you ever wonder what some of those strange radio signal beeps, boops, squeals and braps are when you tune across the radio frequencies? Click the link below for a neat wiki page, off one of The DXZone and Sigidwiki.com website pages, that not only allows you to listen to short audio segments of them but also shows what the signal looks like in a waterfall image.
I stumbled onto this really cool website called RigReference.Com and was able to find some information on several older pieces of equipment I have in my ham shack. Here is what their website says…
Who we are
RigReference.com is designed for and by Ham Radio enthusiasts. RigReference.com provides information about new and vintage amateur radio equipment (rigs) and allows and encourages members to share their opinions about these rigs.
RigReference.com is always looking for amateur related news, especially new equipment announcements. If you’ve seen or heard anything interesting please don’t hesitate to contact us!
RigReference.com explicitly does not sell ham radio equipment and/or parts.
The Icom 718 HF Ham Radio is suggested by many hams as the ideal beginner’s HF rig. The QRZ.COM website had a good forum post on best radios for beginners HF Rig For Beginners (See reviews of the Icom 718 at the end of this post.)
Receive Range: 0.030-29.999 MHz
Transmit Range: 1.800-1.999, 3.500-3.999, 7.000-7.300, 10.100-10.150, 14.000-14.350, 18.068-18.168, 21.000-21.450, 24.890-24.990, 28.000-29.700 MHz
Mode: USB, LSB, CW, RTTY (FSK), AM
Transmit Power: SSB, CW, RTTY 2-100W; AM 2-40W
Memory Channels: 101 (99 regular, 2 scan edges)The HF bands allow you to communicate over long distances covering many km even to the other side of the world. With the superior performance found in the IC-718 such as wide dvnamic range, high C/N ratio, and full duty operation you will find making these contacts easy. Experience the combination of the latest RF and digital technology, along with the size and simplified operation. You will see the IC-718 will be the most practical rig you will ever own.Front mounted loud speaker
The IC-718 has a speaker mounted on the front panel. With the speaker facing the operator, audio sounds can be clearly heard without impediment during operation. It is no longer necessary to manually increase the volume to try and capture audio sounds.
Superior basic performance
The IC-718 has 0.03-29.999999 MHz* general coverage receive capability. A 4-element system is employed for the 1st receive mixer, providing superior receive IMD, especially from in-band near-by interfering signals. A well-designed double-conversion system to help minimize image and spurious responses for better signal fidelity, is also built-in. A newly designed PLL circuit has been adopted to improve C/N ratio characteristics. The combination of the 4-element system mixer and new PLL circuit allows superior basic performance as that of a commercial grade transceiver.
*Guaranteed range: 0.5-29.999999 MHz
The DSP includes the following to give you superior receiver quality in your shack, vehicle or during DX’pedition. *DSP is built in to U.S. models, but may be optional outside the U.S. Please check with your dealer.
Pulls desired AF signals from noise. Outstanding S/N ratio is achieved, providing clean audio in SSB, AM and FM.
Automatic Notch filter:
This automatically minimizes beat signals and heterodynes while preserving the receive signal. Also, the notch frequency is automatically adjusted to follow interfering beat signals – for example, reducing interference from RTTY signals during SSB operation.
Interference rejection – IF shift
To reject interference, the IC-718 has an IF shift function which shifts the center frequency of the IF passband electronically to reduce adjacent interference.
This feature compresses microphone audio input to increase average audio output level. The result is, that talk power is increased. The compression level is adjustable for your preference. This function is effective for long distance communication, or when propagation conditions are poor.
RF gain control
RF gain control is combined with the squelch control. The RF gain adjusts minimum response receiver gain, and ignores signals weaker than the pre-set level – providing pleasant stand-by, or scanning.
Ample CW features
An electronic keyer with a variable dot/dash ratio (2.8:1 to 4.8:1) control is built-in. By simply connecting a paddle, easy CW operation can be made. The CW pitch and the key speed are also variable from 300-900 Hz, 6-60 wpm, respectively. Of course, full break-in capability is available with the adjustable break-in delay.
A VOX (Voice operated transmission) is included with the IC-718. It provides handsfree operation by detecting audio signals from the microphone. It’ s easy! Flexible filter selection
Flexible Filter Selection
An optional IF filter can be installed into the transceiver to suit your operating preference.
High frequency stability
When the optional CR-338 HIGH STABILITY CRYSTAL UNIT is installed, you get a very high frequency stability of ±0.5 ppm.
Selectable antenna tuner
Either the optional antenna tuner unit, AT-180 or AH-4 can be used with the IC-718 to suit your installing conditions, or operating style. Of course, the AH-4 control circuit is built into the IC-718.
The IC-718 is equipped with a minimum number of switches and controls for superior feature selectability. The 10-key pad on the front panel for entering directly an operating frequency, or a memory channel number. The auto tuning steps function helps quick tuning is activate when turning the dial quickly. And the band stacking register is very convenient when changing operating bands.
Digital S/RF meter
Built-in multi functional digital S/RF meter indicates signal strength level while receiving, and either transmit output power, ALC level or VSWR ratio while transmitting.
Optional voice synthesizer
A clear, electronically-generated voice announces operating frequency, mode and receiving signal strength level when the optional voice synthesizer unit, UT-102, is installed.
• USB, LSB, CW, RTTY(FSK) and AM modes are built-in
• Level adjustable noise blanker
• RF attenuator and Pre-amplifier
• Variety of scanning function types
• Total 101 memory channels are available
• Hand microphone is supplied, and more…
• Hand microphone
• DC power cable
• Spare fuse (FGB 20A)
• Spare fuse (FGB 4A)
Dim: 9.4″w x 3.75″h x 9.4″d; 8.5 lb.
Download Manual: IC-718
Download Brochure: IC-718
Afrotechmods is a very insightful and easy to understand YouTube channel to follow on basic electronics. Here he talks about multimeters and their usage in our ham shack. I have several different digital and analog multimeters and their usage often depends upon the application and project. He does other excellent videos, so check him out!
This is why ham radio operators need to be prepared for such a massive solar event. If the rest of the grid (power and internet) were to go down, it could take a long time for it to be repaired. Ham radio communications might become critical in every community. Are we prepared and proficient to aid our communities?
Link to full article… Near Miss: The Solar Superstorm of July 2012
John Shannon (K3WWP) kindly permits me to post his recent article here for your enjoyment. His contact information and websites are listed at the end of this article. Also, check out and join the NAQCC website at http://www.naqcc.info/
You can’t work DX on HF unless you run high power and have a big antenna farm. How many times have you heard that? Believe it or not even one ARRL employee was very skeptical about the ability to work DX otherwise. Maybe still is.
Anyway I’m writing this to dispel that notion. I also do it by example as many of you probably already know. Let me start by describing my station in detail. My rigs since I became active again in the early 1990s have been homebrew, Kenwood TS-570D, Kenwood TS-480SAT, Elecraft K-2, and now the wonderful Elecraft KX3. All have a couple things in common. They have never been used on any mode but CW. They have never been used at more than 5 watts output power (except for two experimental QSOs and one accidental one – that’s another story just mentioned here for 100% accuracy).
My antennas consist of a random wire most of which is in my attic for 160 through 30 meters, a 20 meters flat-top inverted vee in my attic, a 15 meters vertical dipole mounted on the side of my house, a 10 meters sloping dipole on my porch roof, and a 6 meters rotatable dipole in my attic. As KB7MBI puts it, that’s not an antenna farm, that’s an antenna victory garden.
With that setup I have made 19,140 DX (non-W/VE) QSOs since the early 1990s from at total of 219 countries (entities) on all continents and 36 of the 40 CQ zones. Currently as of May 29, 2014 I have made at least one DX QSO each and every day since March 1, 2013 – a total of 455 consecutive days.
With that preamble to let you know that I probably know what I’m talking about, I’m going to tell you how you can do just the same, probably even better if you have better antennas and a better location than I do. Oh, I neglected to say I don’t live on a remote hilltop somewhere, but right in the middle of a small town with its attendant man-made QRN. The town is located in a river valley with surrounding hills making a visible horizon of a couple degrees up to around 10 degrees.
I think the above proves it is possible to work DX with just 5 watts or less output and simple wire antennas. Of course it’s not as easy as working DX with 1 kilowatt and stacked 4 over 4 beams, but it’s not as hard as many hams think. I believe that ANYONE, without a great deal of effort, can get the basic DXCC award using nothing more than QRP/CW and a wire antenna. I worked 100 countries in just the first 78 days of the year 2000 as part of the ARRL Millennium Award program. Here are some tips to hopefully help you in your DX efforts.
Basically there’s not a lot you need to know to successfully work DX. First of all, a lot of good DX is only available via some high speed CW operators, so the faster you can copy, the easier it will be to work the DX station and move on to others. Of course since you don’t really have to copy a lot of info in most cases, you can get by at lower copying speeds. When you get right down to it, all you really need to copy is the DX station’s call, and your own call. But still you’ll be much better off being able to copy at least 30 WPM which is not all that hard to do with some good practice. If you can copy everything involved in the DX operation, you’ll be much more prepared to work the DX.
You also should know something about propagation as I mentioned in a previous newsletter. That way you won’t waste time in mid-afternoon trying to work DX on 80 or 40, nor time in the middle of the night trying to work something on 10 meters. Not to say there aren’t times mid-day DX on 80 or especially 40 is possible, or 10 meters DX late at night, but generally it’s not.
The most important thing to remember about DXing, no matter what power or antennas you are using, is to LISTEN before you do anything. Of course, before you can work the DX, you have to be able to hear it.
Once you find a DX station, you then LISTEN some more to find out the station’s mode of operation and just where HE is listening. For example, if you hear him work a station right on his frequency, then you know he’s listening there. Zero beat him and get ready to call, but again don’t jump in too quickly.
LISTEN to find out the pattern of the DX station’s exchange. When the DX is trying to work as many stations as possible as quickly as possible, the exchange should go like this:
Station – Sends
X2XXX – CQ DX X2XXX K
K3WWP – K3WWP
X2XXX – K3WWP 599
K3WWP – TU 599
X2XXX – TU
Sometimes after the exchange of info, the DX station will just say TU as in this example, and then start listening for replies. Other times he will send QRZ?, or QRZ? de X2XXX, or just X2XXX. Some stations send dit dit. Whatever it is, learn when the DX station is done with a QSO and ready for the next call before you jump in. Do everything right and you’ll have your QSO or at least a better chance at the QSO than someone who has no idea what is going on.
Of course that is the ideal situation, and it is not going to work that way every time, even for the most powerful station in the world, and certainly not for the QRPer with his wire antenna. Not to say it doesn’t happen, though. A few times I have beaten out a fair sized pileup to work a DX station. Why? Often it is simply favorable propagation, but there are also things you can do to help.
Be sure your signal is as clean and crisp as possible and your keying is as close to perfect as possible. DX stations often mention that it is not always the strongest signal that is easiest to copy in a pileup. Often a weaker clean signal with perfect keying is easier to copy. If you have a memory keyer, use that to send your call. It is possible to get nervous when trying for some rare DX, and be sloppy sending even our own call.
Another thing that helps at times is to delay for a second sending your call so that the last letter or two extends past the main buzz of the pileup. In my case, the DX station would then hear the WP and send WP? Then I send my call again, and make the QSO. That is assuming there is no other WP in the pileup, and everyone acts properly and does not transmit again if their call doesn’t contain a WP. And we know the odds of that. Generally anyone who has a W in their call transmits, everyone with a P transmits, and others will transmit even though their call has nothing close to a WP in it. The best of the DX stations in this case will send WP? KN KN and keep doing this until everyone else shuts up except the WP station. If a DX station does this often enough, he can really take control of a pileup and make it manageable.
If you’re totally aware of what is going on, you can sometimes catch a station switching from simplex to split (more about that below) operation, and be one of the first ones to switch. I’ve several times gotten an easy DX QSO that way. Or catching a station switching to another band and being the first one to do so and working him easily. Again that gets back to LISTENING which a lot of folks seem not to do.
If you keep calling him without an answer, try to figure out why. It could be that propagation is currently favoring another area. If he is working one W6 after another, and you are a W1, that could be the case or he may have his beam pointed to California at the moment. This is a good time to just note his frequency or store it in a memory in your receiver, and look for someone else. Come back later and see if the DX station is working stations in your area. If so, jump in and try again.
Some QRP stations like to sign /QRP at the end of their call in a pile-up. I don’t think it’s necessary, and I NEVER do it for the following reasons:
1. I don’t feel my QRP should be pointed out as a special situation. I’m just another station in the pile, not someone special because I’m only using 5 watts or less.
2. I am sure some QRO stations cheat and sign /QRP, and I certainly don’t want to be accused of that by those who don’t know that I am a 100% QRPer.
3. It does take an appreciable amount of time to send /QRP when you are dealing with running hundreds of stations per hour, especially if it has to be repeated. If I make a contact, there’s a chance I’ll have to repeat
my info since my sigs are weak, and repeating /QRP along with the other info may annoy not only the DX station, but others waiting in the pile. I hate slowing down DXpeditions or contesters like that.
4. To back up what I say in item 3 above, famous DXpeditioner G3SXW in his book “Up Two” urges operators calling him not to use /QRP. Then there is this quote from the 3B9C DXpedition web site to further denounce using /QRP: “We have received a few e-mails demanding that we amend logs to show /QRP. We are aware that some operators at 3B9C have been logging /QRP but it is DXpedition policy that we do not do so. /QRP does not form part of the legal callsign in any country and, as far as we are aware, no QRP awards require the callsign to be suffixed with /QRP. Therefore the /QRP suffix has no place in the 3B9C DXpedition log. You know whether you worked us on QRP or not and that should be all that is needed.”
If a pileup gets too huge and the pile obliterates the DX station, then the DX operator will switch to split frequency operation. This is when the DX station transmits on one frequency, and listens on another, usually higher, frequency.
If you hear a DX station say UP (or UP1, UP2, etc.), that means he is listening to a frequency higher than his. The number is the number of kHz higher than his transmitting frequency. Leave your receive frequency on the DX station, and set your transmit frequency UP to where the DX is listening. If he just says UP with no number, generally that means UP 1, but not always. Then you have to find the pileup yourself. Once you determine where the DX station is listening, follow the same procedures listed for simplex or same frequency operation. Just be sure you are transmitting and listening on the right frequencies. Every rig seems to have a slightly different way of accomplishing this. I’ll describe two ways it can be done with a KX3.
1. Tap the A>B button twice to copy the A VFO frequency and settings into the B VFO. Hold in the A>B button to activate split operation. Now the A VFO shows the receive frequency, and B can be tuned with the B VFO knob to set the transmit frequency. Then if desired, the headphones can be split via a menu setting so the DX is heard in the left ear and the pile in the right ear. That way you can hear who the DX is working in the pile in your right ear and the KX3 will then be set to transmit on that frequency.
2. Use the XIT feature to offset the transmit frequency from the receive frequency.
I always use #1 above, so I’m not totally familiar with XIT operation.
If the pileup is huge, you might be better off transmitting slightly higher than the main pile. The DX station will often explore the upper (usually) edge of a pileup if he can’t pick out calls from the main section of the pile. This is where the clever QRPer can often steal a QSO from the QRO stations. It’s really a chess game, and whole sections of DXing books have been devoted to breaking a pileup.
Often times the DX station will be operating split frequency but not saying so. This is where listening comes in. If you hear the DX working one station after another, but don’t hear any of the stations he is working, it’s time to tune UP and see if he is indeed working split frequency. Or you can go ahead and transmit on the DX frequency, and the self appointed DX policemen will very impolitely and illegally tell you the DX is listening UP. It’s always better to know what’s going on before you do any transmitting.
That’s enough about the pile-up type of DXing. If you want to know more, just get on the air and practice, or read one of the many excellent books that have been written about DXing.
Let’s touch on a few other DX topics at random. What about the QRPer calling CQ DX using his wire antenna. It’s probably useless most of the time, but I have had DX stations answer my regular CQ’s many times. This usually happens on 10M when conditions are really good, but it also happens on other bands. I currently have about 3 dozen countries worked via answers to my CQ’s. Strangely, my most distant QSO ever came when VK6HQ answered my regular CQ on 30M one evening. I was so shocked and excited I could hardly send. Even after the QSO, I was wondering if it was really true that I worked a VK6. It was, because I received his QSL card in a couple of weeks. However something like that is the exception rather than the rule for QRP CQ’s. Once in a while lightning strikes twice and a couple years later John, VK6HQ again answered my CQ on 30M. This time it led to a long distance phone call from John, and follow up Emails between us. This is one of the rewards of DXing – having one of your contacts become a friend.
The easiest time to work DX is in contests, because the best operators in the world often go to exotic locations for contests to make themselves more desirable or just to activate some rare country. Plus you have the super contest stations in various countries operating with their huge antennas and state of the art receiving equipment. They are the ones who can dig out the weakest of signals, and are glad to do so for those few extra points they will get in the contest. Those points may just help them beat out another top notch contester. You may have a tough time beating the pileups at the beginning of a contest, but often these super contest stations almost go begging for QSO’s near the end of a contest period. Then is the time you may easily work them.
Also for the week or so just before the big DX contests, many of the stations setting up for the contest will check out their equipment by working as many folks as possible. At these times they may also operate on the WARC bands (30, 17, 12) which are not available for operation in the contest itself. They often stay at their locations for a few days after contests also.
Always let the DX station dictate the type of QSO. If you answer a DX station outside a pileup, and he still sends just a report, you do the same. You will earn the respect of the DX station and those working him. There’s nothing more frustrating that having a DX station send only RST and the station working him sending seemingly his entire life history. If the DX station does send something like RST, QTH, and Name (OP), then you may be fortunate enough to find yourself with a DX rag chew. Send your QTH (maybe just the state), and name, and maybe mention you are running QRP. It doesn’t happen too often, but I have had some very nice rag chews with DX stations. I recall a few I especially enjoyed. I chatted for a half hour with a German who was on vacation in the Canary Islands. A PJ2 wanted to know all about my QTH. I had a nice chat with an Italian talking about my Italian heritage (my mother was Italian). A German asked me all about my QRP rig. A station in Haiti was new to operating CW and asked me several questions about it.
There were others as well. These are the DX QSO’s I find really rewarding, although I appreciate the RST only ones also. You CAN rag chew with DX using QRP when conditions are good.
There’s much more good info about DXing on my web site at http://home.windstream.net/johnshan/. I hope you’ll visit. I also hope you’ll be as successful as I have been working DX. I KNOW you can be if you just apply yourself.
73 and gud DX.
* John K3WWP – 100% CW / QRP – Proudly promoting Morse Code:
* On the air with my KX3 #2325, K2 #6418, KX-1 #02101
* As NAQCC VP – # 0002 FC # 1 – http://naqcc.info/
* As FISTS Keynote QRP Columnist – # 2002 – http://www.fists.org/
* With my CW-QRP site – http://home.windstream.net/johnshan/
Another great YouTube show! Ham Nation
This episode speaks about hooking up and audio mixer to your transmitter with Bob Heil and Gordon West, et al. Every show is packed full of information about many different facets of the hobby. Watch them all! (Segment begins at 41:45 in the video…)
Hosts: Bob Heil (K9EID), Gordon West (WB6NOA), George Thomas (W5JDX), and Leo Laporte (W6TWT)
I have built four different radios from Ramsey and they are fun to build, easy to layout, and you learn a lot of radio design. Built the 40 Meter QRP Receiver and Transmitter, the Aircraft Receiver, Infrared Transmitter and Receiver kits. A great way to pass a rainy day! (Click link below to go to their website…)