Sorry this a slightly little off topic (but not nearly as much as ISO9001 compliance). Anyone know where I can get right-angle motorola connectors (e.g. the standard male car radio connector). Specif
yesterday and pulled the driven element level to the ground (It was a little off) and water came out of the traps... That solved the SWR problmes however the RX on 20 is still about the same as the d
Jim/Tom, If the portion of the coil inside the tube isn't used, couldn't you just add extra finger stock contacts at regular intervals along the inside length of the tube to short out the unused turn
Mark, I was in the same situation as you several years ago (e.g. I picked up a used cantenna at a hamfest). I dumped the old "unknown" liquid into a plastic jug and drew a skull and crossbones on the
Jim are you sure about that? The reason I ask is that both the Heath and the MFJ Cantenna style dummy loads specify duty cycle curves for mineral oil and "transformer oil". For 1KW, the duty cycle fo
The are nominally the same, but I am not sure that I would want to use Diala-X or gear oil as a laxative :) From the bit of googling I did this afternoon, it seems that mineral oils are all nominally
Its interesting to watch the posturing of folks when a claim like this comes along. When some people express skepticism, others chime in and accuse them of being "close-minded". This is wrongheaded.
Hi Bill, Using Keven Schmidt's TL Calculator http://fermi.la.asu.edu/w9cf/tran/index.html I got 0.39 dB/100' for 450 ohm windowed line and 0.54 dB/100' for 300 ohm tubular line. This is about what yo
Todd, Seems to me that you want to find some way to emphasize that the exposure your neighbor will get from your installation is way way smaller than what he will get from having a cellphone in his p
I concur. I had a friend who was going through a tower permitting process that included notification of neighbors. One of the neighbors, a medical doctor, started writing letters warning the other ne
One of my colleagues at work fly's model Helicopters. Seems like a model helicopter with a small beacon transmitter might be the way to make a poor man's HF antenna range. Alternatively, a tethered h
This is easy enough to test for. Put the voltmeter or soundcard on the receiver output. Feed the receiver with a steady source like a signal generator, and then use the calibrated step attenuator to
Jim, You may have seen one of those dual square boom logs where the coax runs into back-end of one of the square tubes and then all the way up the inside where it attaches to the feed point at the fr
same If For receive only, yes. For transmit, don't count on it being an easy design. Even if you can get the inductor unloaded Q's up above 500, you are still going to have pretty high insertion loss
available, If you use the MFJ style noise cancellors, you could do it fairly cheap. Standard stubs or lumped element bandpass filters will take care of crossband interference. The noise cancellors wo
from miles of won't solve on severely limit MFJ is better? You may have a point, Jim, but remember the ANC4 and likewise the MFJ unit (I think) have all the active gain in the noise leg. This is the
You may have a point, Jim, but remember the ANC4 and likewise the MFJ unit (I think) have all the active gain in the noise leg (come to think of it the MFJ may have gain in both legs). This is the co
Yes, trying to match delay overy frequency would be a nightmare in a field day situation (we are lucky to get all are stations up and running in time for the beginning without the burden of fancy nul
Its interesting to see how antenna spacing plays into this Jim. I just ran a couple test cases in EZNEC using two 20 meter 1/2 wave horizontal dipoles at 40ft above average ground. The antennas were
We have a big water tank at our Field Day site, Jos. We were thinking it might make a good 20 meter cavity. Of course, I don't know if the U.S. Forest Service would appreciate it if we drained out al