I'm guessing that the transmitting antenna is going to need some real work to get it appropriately detuned. Remember, the K9AY is lots of dB down in absolute signal level, meaning its rear null is ve
Yup, then you just need to deal with the feedline loss... but... Most of the time no one actually needs 1500W ERP on 17m/12m to work DX .. so that's a consideration if you don't usually care about 1
40.64 cm = 16 inches exactly. The metric-conversions.org doesn't give an error for the comma as decimal seperator. It simply ignores everything after the comma, or any other character. For example 16
Some info on this here: http://www.k2kw.com/verticals/tests.html 73 Dan _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTal
Yep. Not one of these emails hits my inbox. They all get labeled and archived ... so when I want to read TowerTalk, I click on the little "TowerTalk" label link in Gmail. I've got an automatically f
It's not 3dB, it's 2.15dB And as far as I'm concerned dBd = dBi +2.15 is a totally useless definition. No offense intended to you, it is a "true" thing and is indeed indicative of the FREE SPACE situ
I think I found what you're looking at ... different spot in the Fourth Edition, figure 9-11 on page 9-7 in the "Vertical Antennas" chapter. There's a figure with four antennas, starting with 0.15 w
On the group's average 0.5dB accuracy measurement range??? :-) I don't see anything in there that is a reason for implicit mistrust of the model. A helical is better than a high Q base loaded vertic
Probably a problem with insufficient feedline choking, IMO. You should be getting 12-15 dB F/S on 7MHz and 10-12dB on 5.4MHz if you don't have radiation from the tower or feedline or whatever. 73 Da
The amount of size reduction you get out of dielectric loading depends on the effective dielectric constant of a large volume surrounding the antenna. If you built a yagi in an infinite space of sol
10dB 2.5dB dB/100ft is a strange type of unit but since the loss has an exponential dependence on length, it makes sense. P(x) = P_o * 10^{-a*x} where a is an attenuation constant per unit length in
Jim, of course you gave the right answer overall, and of course you meant you "double the dB loss" but this sentence is the crux of the issue, so I want to expand with a few examples. You don't "doub
You can get a big jar of compression fittings and a tool at Home Depot for not much money. Think the tool is only about $15 and works fine. I have a lot of "RG-6 quad shield" stuff around here in use
I'm going to assume that a "kills wasps" thread is reasonable fodder for TowerTalk because it's a legit safety issue ;-) Ordinary soapy water kills any insect pretty fast. Cuts off their oxygen. Very
I don't have another meter, but I use my MFJ-259B to measure inductances and capacitances and I find that it works well and compares favorably with calculated values of inductance and labeled values
The test that actually pulls apart test samples until they break measures the "ultimate strength" The yield strength (actually yield stress, in pounds per square inch) is where the material just sta
Yeah, if you consider someone who's wearing only two wraps of clear Saran Wrap to be "clad." The mild steel MIG wire I've had here comes with a copper flash on it that I think is juuust enough to ke
I've seen a picture of the interior of one of the DX Engineering line isolators, I guess in QST, and it was three chokes in series, each of which was a multi-turn binocular-style (not truly binocular