I was looking for a good demo on how to adjust the AGC or "Automatic Gain Control" on my radio and came across this good information from Bob Heil K9EID. Good information especially with the tip to LOWER your RF Gain. I tried it today on some 20m signals and it really worked and made the received audio much more readable. And the bonus is that the first segment he played was taken from my favorite 40m net "The Hole In The Wall Net" which is daily at 9pm on 7.188 mhz. Get your radio fired up and test this... it worked great on my FT-DX1200.
Comparison - New FTDX10 vs IC-7300
Here is an informative video from one of our favorite sources. Ham Radio Concepts has a fantastic channel on YouTube. You can find it here ----> HRC on YouTube
The new Yaesu FTDX10 is a nice addition to the brand. It's lower price than the FTDX-101D but using the same "bones". Early reviews are good. Check out this nice comparison review. Also look to the SEKARC email list for a review from Morgan NJ8M. Great information and thanks Morgan.
Solar Cycle/Propagation Refresher
With the recent spike in solar activity and the Solar Flux Index being over 100 for the first time in years I thought this would be a good time to give myself and those interested a refresher in Propagation. Enjoy and get on the air.... the bands are waking up!
BYOC QSO - LINCOLN PARK
SEKARC for several years has met at Harry's Cafe every Wednesday at 9am.... then Covid came along. Some have expressed interest in getting back together so we thought we would try something a little different. Let's have a BYOC or Bring Your Own Coffee QSO Wednesdays at 9am.
Also, while we are at it maybe have a little tailgate/trade at the same time. While reducing boxes and tubs in my garage I came up with a tub of stuff I don't need but someone might so if you have something to pass on, giveaway, sell or trade while we are drinking our to go coffee and eating breakfast in a paper wrapper. Not the same as Harry's fresh breakfast on a hot plate but under the conditions this might be a good bet.
Of course masks and social distancing will be requested so bring a lawn chair or sit at the picnic tables at Lincoln Park. We will meet just West of Kiddieland. Heck if you want to and the weather cooperates bring a radio and antenna and set it up!
So grab breakfast and coffee on the way, dig through your stuff and find some stuff to bring along to see if someone needs it. I have a tub full, and I bet a lot of us do. We understand if you are not up to it or would rather not. Let's all stay safe but still have fun if we can.
RADIO FUN WEEK - GET ON THE AIR
We plan to operate all HF band from 160 to 10m
Many different modes!
VHF 6m and 2m depending on openings
Mostly SSB maybe some digital modes
WiresX SE-KANSAS 46341 Call Radio Fun Week
The email group has a link for the script and sign up sheet for the timeslots/band/mode you plan to operate. When you operate use callsign WØF. Per special event regulations you need to announce your own personal call once per hour. If you have any questions please ask on the email group or find us on the .24 repeater also. Key is HAVE FUN!
HamShack Hotline
Hamshack Hotline is a private VoIP telephone voice network for Amateur Radio. This could be a very valuable tool for emergency communications to take some of the load off of radio networks. Setup was extremely easy all that was needed was a supported device which at this time are only Cisco VoIP phones. I purchased my Cisco SPA504G from eBay for $35 free shipping. Please make sure the phone you order is UNLOCKED!!! This is very important.
Setup was super simple i followed the instructions and started a support ticket with my phones MAC address, connected my phone to my network via Ethernet and noted it's local IPv4 address. Once i received the response from HamshackHotline.com i plugged the IP address into the URL in the instructions and BAM!! the phone reset and my callsign and number showed up on the phones display!
I know some hams have a thermonuclear meltdown when talk of using the internet for emergency communications comes up! My opinion on the matter is having as many forms of communications as possible is key in an emergency. The likelihood of the the internet being down everywhere is very low now days and this system could help reduce the load on radio networks in time of emergency. Amateur radio and the internet will become more and more intertwined as time goes on just as freezers and light bulbs become connected to the internet.
As ARES EC for Crawford County, KS i plan on getting these phones for all of my AECs and as many members as we can. The one BIG thing that is missing from Hamshack Hotline in my opinion is mobile access to the system. Mobile access could be mobile SIP app or even a bridge number you can call a public number and enter a PIN to access the system. A similar system Government Emergency Telecommunication System (GETS) does just that. You have a GETS card with a PIN number that you can call it will give your phone priority over others for emergency communications. People with GETS access could even use GETS to call a bridge number for access to HamshackHotline in an emergency!
Amateur Radio operators have access to so much microwave spectrum! A microwave IP system could easily be connected to the internet via multiple redundant paths many miles apart. These IP networks could not only HamshackHotline but many other IP services that could continue to work in the event of an emergency. With future Low Earth Orbit (LEO) satellite internet access services like SpaceX StarLink that have extremely low latency one could have highly survivable IP connections anywhere!
The ultimate selling factor for me for Hamshack Hotline the fun / cool factor of having this cool IP phone on your desk in the hamshack! It's cost less then taking the family out to dinner in the $20-40 range! Operating the Hamshack Hotline network requires money so please support them if you want to use this system just a few dollars per year per user is all that's needed!
EDIT: 9-9-2020
Other ARES members received phones and got them setup so far the system just works. I went through and setup voicemail and in the message i put my Public Switched Telephone Network (PSTN) number so people could call me if they need me outside of the shack.
I used a 12v to 5v DC-DC converter to power my phone off of my 12v solar backup system. All of my networking equipment is ran off of battery backup and i have fiber to the home. My fiber provider is 100% underground and mostly passive all the active equipment is in hardened buildings. This is not guarantee that the network will work during large power outages but it's better then nothing. I also have the capability of feeding my network from cellular LTE as a backup.
73 de Tyler KB0PQP
How Does A J-Pole Work?
I still am learning about antennas... and I am sure many of you will
agree with me. From new hams to long term hams this is interesting.
Check it out and Dave does a great job on all of his videos!
Zoom Meeting Saturday July 25th
Time for the monthly SEKARC meeting. Again this month we will hold the meeting on ZOOM. It will start at 9am on Saturday July 25th. We have a few topics to discuss like considerations on proceeding with Covid, Planning for the Fall special event and talk about participation in the Joplin tailgate event which is replacing the hamfest.
If you have not used ZOOM it is really easy so give it a try. Everyone interested is welcome so if you are on our email group you can get the details there. If not, feel free to join our group or email one of us or the club email on QRZ. The club call is KØSEK.
W1V Special Event - Maine WS1SM
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This looks like a fun event and a certificate that would be a nice addition to your shack walls! This group, the Wireless Society of Southern Maine is very active and you can also follow them on InstaGram, Twitter and Facebook! They do a LOT of Island and Lighthouse activation events.
Field Day 2020 - Covid Version
This is a great video for everyone regarding Ham Radio Field Day 2020. It covers a summary of what FD is and also details the rule changes for Covid 2020. This would be a good link to share even with your non licensed friends on various social media platforms.
Thoughts On Inductively Loaded Dipoles
Or... How To Get 2 Bands On 1 Wire
By Morgan Bailey NJ8M
By Morgan Bailey NJ8M
Having wires strung all over the place on a city lot is not something that the neighbors like seeing done. Keeping the landscape as clean as possible is a good thing, both from a real estate perspective and from an RF interaction consideration between antennas. Also, small lots many times present challenging problems to solve in size and visual impact. Using less wires and giving the amateur operator more bands can be solved by making wire antennas a multiband approach. My solution that allows me to run 1500 watts without problems is to construct an inductively loaded dipole. Alpha Delta antenna products have many products that do exactly that, but why do they work and can they be designed for other frequencies? The following is, I hope, a simple presentation of how to design any dual band antenna using coils to make it fit on your lot. I want to site an excellent website by K7MEM.COM. He has done a bunch of work on shortening antennas but I wanted to take it a simple step further and present my reasoning and how to design any dipole to be a dual band antenna, especially on 80 and 40. This seems to be the problem for most amateurs to solve.
Questions arise as to how to proceed without using engineering approximations which falls under the heading of a Wild-Ass Guess. Cut-and-try engineering will work but it takes time and many don’t have the patience to succeed. Hopefully, my approach will cut these approaches to a minimum. Problems with inductively loaded dipoles are mainly the ease of construction, the location of antenna and narrowing of bandwidth of the second band. The use of an antenna tuner, matchbox, to increase bandwidth, predicates not using a center balun. High SWR will toast a balun. For this reason AlphaDelta does not recommend a balun and specifically states in their literature that is shipped with the antenna that the “the antenna is designed to not be used with a Balun.” Many would argue that without a balun, the pattern will be changed, specifically, on 80 and 40 meter bands. This is a non-issue because very few amateurs have the ability to put a dipole at 60 feet for 40 meters, much less 120 feet for 80 meters. So, mainly the city dweller will have an NVIS antenna with a center fed dipole up 30 feet and because, most amateurs don’t have 3 supports to make it a flat top, will be using the inverted Vee approach. This is just fine because it gives an omnidirectional pattern and lowers the feed point from 70-72 ohms down to 50 ohms which is what RG213 and RG8X, RG58 and LMR400 coaxes are designed for. Putting up a dipole with an included angle less than 90 degrees falls under the, “ Any antenna is better than No antenna,” category. In general, put a dipole up as high as you can and make the included angle greater than 90 degrees and you will be a happy camper. Don’t worry about DX, I have worked DX from Kansas using an inductively loaded dipole up 20 feet. Is it the best choice, no, but if it is your only choice, you are good to go. Now for the theory, as a general class op, you will have already seen the theory in the test question pool. We will use 2 formulas from that and a third for calculation of an inductor based on turns per inch, wire size and length of coil.
The first formula is the frequency of a half wave dipole:
468/frequency in Mhz = Length in feet of a half wave dipole
This is the pure theory that proves out. Variables are added when you don’t use bare wire. The use of THHN wire from the big box stores is the common go to for antenna building. I use #12 black insulated THHN wire that comes on the 500 foot spools for around $50-60. The insulation adds a velocity factor that shortens the antenna. This is not a factor because trimming the antenna to resonance will be done empirically based on the location and installation of the antenna. In general, it is better to cut longer because it is easier to trim off rather than add because it was too short. I generally add 4 feet to the measured length for 80 meters and 3 feet for 40 meters. This gives me plenty of length to resonate by trimming the length and to terminate the ends and center connections that are necessary. Because of the velocity factor of the wire, it will be longer. Add the length any way. In this case, more is better! That takes care of the basic dipole construction of a single band antenna. Now let's add a second band by using a coil, inductor, and shortening the lower frequency length but keeping the higher frequency un-affected.
Any dipole can be made into a 2 band dipole by trapping the higher band with an inductor and thereby shortening the lower band length. The added inductance at the higher frequency shorts out the longer wire after the coil. At the higher frequency of the dipole the center dipole does not see the wire beyond the coil. At the lower frequency the inductor adds inductance to the dipole, RF flows through the inductor and by trimming the tail of the antenna, it can be made to resonate on the lower frequency with a greatly shortened length being made possible, thereby making it a dual band dipole with a single feed point. This cuts down on coax runs and decreases cost to the new amateur. So how much inductance does it take to make this magic happen? We need to address how much resistance at a given frequency of operation is necessary to present a resistance to flow of the RF in the wire. I want to simplify the theory of operation by using common sense, which in today’s environment, is rather uncommon. Let us look at data that is easily obtained without any experimentation but just by reading the specs of a product already in production. That being a choke balun used on coax to stop the flow of RF on the shield of coax. Going to BalunDesigns.com and looking at their graphs for these baluns it is found that 3500 to 4000 ohms is enough to get the job done. That was easy. Now lets build a coil that has inductive reactance at that frequency giving the 3500-4000 ohms necessary to get the job done. Ok another formula:
Inductive reactance in Ohms = 2 x Pi x Frequency x Inductance
Yes we can solve the equation, but it is easier to just go to a web site, plug in values till you get the right resistance needed, 3500-4000 ohms, and get your answer easily. One such site is:
It will give you 2 boxes to fill in. For an 80/40 dipole, you will want to stop the RF of 7Mhz from going beyond the inductor/coil. Entering the frequency of 7Mhz and a random inductance to play with to get to the desired 3500 ohms of resistance/reactance necessary to make the coil, one arrives at 80 microhenries. Because this equation is linear, that is, it scales directly, then by this logic a 20 meter coil will take 40 microhenries and an 80 meter coil will take 160 microhenries to provide the necessary values to obtain the 3500 ohms needed to isolate the end wire from the center dipole. Using a smaller value of resistance, 3000 ohms, and even using 3500 ohms will sometimes cause an interaction between the shortening of the end wire changing the resonant frequency of the center dipole at higher the higher frequency, and vice versa. If one goes to 4000 ohms this does not happen. It is like a switch that is an open circuit to the distant piece of wire. This makes resonating the dipoles easy as they do not talk to each other. First trim the wire on the center dipole then trim the end wire. This will greatly shorten the dipole length on the 80 meter band to around 80 feet over all. The band width will be lower, maybe about 40 Khz on 80 with 200 Khz on 40 meters under 2:1 SWR.
How does this shortening affect the radiation of the dipole? Since the main current of a dipole is radiated from the center, that is, the current is highest at the center of the dipole and lowest, going to zero at the ends, it has little noticeable effect to the receiving station. Simply stated the receiving station will not be able to tell the difference between 100 watts and 70 watts radiated power. It works just fine. This effect only applies to the lower frequency dipole. The center or higher frequency dipole is unaffected because it, itself, is not shortened. Only the lower frequency is shortened. To decrease this effect of shortening the length of the lower frequency portion of the dipole and increasing efficiency, one can use a value of 3000 ohms and still produce a 2 band dipole, but there will be interaction when you trim either the center or the end wires on the respective dipoles. I settled for the middle ground and my 80/40 dipole is 108 feet long, which is down from 133 feet. It is between 80-90 percent efficient. It fits in my lot. I’m good with that.
Now for the last equation. How do we make a coil with the given inductance needed to isolate the higher frequency from the lower frequency one? The formula is involved:
Single Layer Coil D L One Turn - N D2 × N2 L (uH) = ------------ 18×D + 40×L Where: D = Mean diameter of the coil (inches) N = Number of Turns L = Length of the coil (inches)
Life is too short to do this math. Just go to the web page:
Plug in the values of inductance, the wire size you have on hand and the coil forms available for the PVC that you have on hand and you are good to go. Happy coil making.
I have made many coil loaded dipoles and here are some Pix of the coil construction:
These coils are made for 3.5 Mhz. They were used on a 160/80 meter dipole. Later one of these was used on my home station in the construction of an 80/160 meter Inverted L which is currently in use in my backyard. They are made with regular 3 inch PVC which measures 3.5 inches OD and wound with 14 gauge magnet wire. They laugh at 1500 watts RTTY.
Once the coils are wound a liberal coating of liquid electrical tape is applied. While this is wet, Scotch 88 electrical tape is applied with over lapping 1⁄2 to 3⁄4 width. Doing this while the liquid electrical tape is wet sort of vulcanizes the tape and makes a very solid construct that is highly resistant to abrasion. It is weatherproof and UV resistant.
The finished product is on the right with the treatment of liquid electrical tape and Scotch 88
tape. It is ready to be installed. The Inductance did not vary before or after the protective
treatment. It still measured 174 microhenries.
I usually cut and trim the lower frequency dipole for the phone portion of the band I want to
operate. This makes it way too short for the CW portion of the band which is my primary
operating frequency. To solve this, I add an end insulator made out of cheap Sams Club cutting
board.
See below image. I use heavy 10-24 hardware on the insulator. It is what I had and the wing
nuts with a lock washer are easily removed. Using a phillips screwdriver for the phillips machine
head stainless steel bolt helps facilitate tightening the pigtail to the insulator.
This way I can add a pigtail that dangles to adjust the frequency downward. I also use this same
construct if I know that I am going to be moving the antenna and will need to re-resonate it at a
different location. Just soldering on a ring connector and bolting it to the nut makes easy work of
frequency change and tuning.
Conclusions:
Both my son, NS0R and I have used these antennas for years and there have been many 10s
or thousands of QSOs on them running between 100 watts to 1500 watts with no problems. I
made one for Field Day which my son cobbled on to and uses at his home QTH on 80 and 40.
We later added a second wire from the center conductor for 20 meters and made a fan dipole
out of it. No interaction was noted by this modification. This is his only antenna. Using this
construction technique at my home station in the creation of a 160/80 inverted L, has enabled
me to get on 160 meters from my city lot. If you have questions:
Morgan Bailey NJ8M
Cell: 785-554-5561 24/7
( If I don't answer right away, I am probably listening to the bottom end
of 40 with my headphones on.) es 73 Cheers!
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