Per request from KEØKRO, here is the chart showing the derivation of the formula that the length in feet of a dipole is 468 divided by the frequency in Megahertz.
Also, you can go here for a higher resolution PDF for printing the entire presentation.
This appears in the video “Frequency, Wavelength, and the Speed of Light (Ask Dave 358)”.
Still recovering from bad episode of gastroinstestinal bleeding. Very anemic at the moment, on oxygen, at home, but trying to walk more than 10 feet leaves me exhausted and completely out of breath. Had 3 units of blood last week. Will try every week to do livestream on Thursday evening, US time, 7pm Mountain standard time. 73, Dave, KEØOG
My article on exploring radio mathematics was just published in the November issue of QST. Unfortunately errors crept in, which has generated lots of emails. I put together a page on my website that collects and collates the errors. Check it out here.
Here’s the drawing that goes with Ask Dave 302. Click here to get the pdf.
The Amateur Extra training videos have been updated to the 12th Edition of the ARRL Extra Class License Manual for Ham Radio, and are once again available for purchase. Please note these are the same videos that are on YouTube, which you can watch for free. The videos-on-a-thumb-drive are offered as a convenience for those whose network connections aren’t good, or want to study away from where they can get Internet access. These video sticks are also handy for those who might want to use them for club presentations or a club-sponsored class.
You can order the thumb drive with the Amateur Extra videos by going to this order page or by clicking on the PayPal button below.
US$49.99 Postpaid US only. Colorado residents add sales tax.
Non-US please contact me regarding shipping charges. Please see the order page for conditions.
PLEASE NOTE: Although my videos are free for viewing, they are all released under the standard YouTube license, which forbids copying. If you need an extra video stick, please order one.
Brad Rich provides this link for those wishing to learn more about DSTAR. Note it not only has lots of good info, but lists other links as well. Here is the link; you can just click on it to go there: www.dstarinfo.com.
Male end of elbow connector, photo by AC3EK, used by permission
Harry reports: “I had asked about erratic power behavior on the ICOM 7300 on the mode FT8 last Saturdays Q&A. Well it turns out it was the elbow connector I had in line on the back of the rig to my jumper going to my MFJ-697 dummy load/SWR meter. Being a Field Engineer, back the day, with Hewlett Packard Medical (1969-1979), I applied the good ole troubleshooting methods. Lightly tapping on the back right hand corner of the cover to the rig, when it was in the tune function of FT8, I could eliminate the problem, i.e. recover proper power output. Next I grabbed the body of the elbow connector and ever so slightly rocked it and sure enough the problem appeared/disappeared. Next, removed the connector and placed the jumper RG8X directly into the rig. Problem went away. I tapped the top- while in tune mode, and no repeat of the problem. Talking to a fellow ham buddy about this He heard that these elbow connectors can be a problem. Notice in the attached photo (Taken with a Nikon 7000, Sigma lens set for micro photo 1/1000 at F13) of the pin of the male part of the connector in the blown up photo notice the scarring to the pin. Thought I would share this for your library of troubleshooting connectors issue. All is good now!! 73s Harry AC3EK”
In Ask Dave 265 and Ask Dave 266, I mentioned an Addendum to the MFJ instructions. This addendum describes that the antenna comes pretuned too long and will need to be shortened, and gives instructions for doing so. See the addendum by clicking here.
I’ve put up a page that takes you to the Reference Station list of equipment. It’s at www.dcasler.com/reference. Check it out. Comments should go to the video that introduces the reference station component.
In today’s livestream, I promised to put up a link to my wire stripper. They’re a bit expensive, but I don’t know how I ever lived without it! Note: if you purchase through this link, you’re helping to support my channel.