the KiloMike: The adjustment of the gamma match was not addressed and it looks wierd all the way to the end. Flip it over if you want it vertical for FM. The mast does not need to be grounded, the elements work in relationship to each other. Want more elements ? Male them a little shorter or the same as the last director. Space about the same. Check online yagi calculators.
Rob Lawrence: hi Dave,, ive just built this 2m yagi plus gamma match,, my first build ;) i enjoyed the build, thanks for the great videos,, im fairy new to 2m radio,, you say this antenna is horizontal for SSB so do you mean if i turn it vertical,, i can use it for FM ? cheers Rob
haassman: what is in the middle of your gamma (the white insulator....with copper). Can you not just use the element, or double aluminum elements up together? When do you have to use a type capacitor in line with the coax?
joee2047: when you wrapped the copper part of the gamma match on the pin of the coax connector and than soldered it,,,, it was only to the center pin and not touching the side at all,,, is that correct,,, just so I know,,,, thanks!!!!
umajunkcollector: Looks as good as a Cushcrap. I like it, and think i'll try to emulate it for 2m ssb. Now all I need is an old TV antenner.
Djordje Marjanovic: Can I use this type of antenna for WiFi signal
Owen Baldwin: Dave, excellent videos on all your projects, very instructive and educational. Well done young man you are an inspiration to young amateur enthusiasts. All the best 73 ...Owen G0RCL
joe s: how would i build a 900mhz RF yagi antenna i love this stuff
Dave Tadlock: Normally all the elements are grounded to the boom when using a gamma match. An antenna with a dipole driven element uses an insulator to separate the two halves of the driven element and can be used to insulate it from a metal boom. Dipole fed antenna elements can be mounted on either a non-conductive boom or a metal boom using insulators. Hope this helps and thank you for watching! :)
Dave Tadlock: No. The driven element is attached directly to the boom. More information about building this antenna is on my web site. The link to my web site is on my YouTube channel. Click my username, then click the Feed tab. The link is in the upper right corner of the page. 73 and thanks for watching! :)
honeybees1: Is the driven element isolated from the rest of the antenna?
Dave Tadlock: It was fortunate that the holes that I reused were spaced 12-3/8" which is an optimal length on two meters. The TV elements have also been trimmed to the correct lengths and were calculated using yagi antenna modeling software. This old TV antenna has been completely turned into a terrific little 2 meter amateur radio antenna. ;)
Jackupnow: Hi would please do a video on a 6 or 10 element beam for 2 m
Jackupnow: Thanks mate very useful info
Dave Tadlock: @bognapalm If I remember right it has something to do with the formula for calculating a series LC circuit. The formula is in my old advance class study guide but I'll have to search for the book. Some yagi antenna modeling software, many available for free download on the internet, will calculate the length of the gamma rod for you. As for this style of gamma match you could scale it down for the 70 cm band but it might be a bit long and unsightly if used on a lower band such as 10 meters.
bognapalm: Is there a formula to calculate a gamma match for different frequencies?
Dave Tadlock: @zx636racer Element spacing is mentioned in part one. I simply removed the plastic TV antenna insulators and used the same holes to mount the elements. The spacing is 12-3/8" between all elements.
Dave Tadlock: @virtualbush Yes, the adjustment may be a bit tight. To increase frequency I could have made the gamma tube a few millimeters longer. Sliding only the grounding strap inwards seems to lower the frequency. SWR will of course also change with height and vary depending on the coax cable length. Thanks and 73! :)
virtualbush: Perhaps some demonstration/information (A short Part 3?) regarding how to tune using the gamma in case the SWR is a bit higher than we might like. Enjoy! I will indicate that we would slide the tubing either in or out over the dielectric. Hopefully not inward in this case because your assembly is tight!
Dave Tadlock: @matthewz07 Have fun with your new antenna and good DX! :)