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...and also be sure to keep a good eye on your Variac output voltage. It is a good idea to use a multimeter, because line voltages can vary quite a bit. This is especially true during the Summer months when the power company is trying to manage peak hour power demands.
Also be sure to check...
Say that backwards and then you would be correct. Just as you would do so when choosing a power supply, you need to use a Variac (autotransformer) that has a maximum load rating in terms of AC current or power (KVA), that exceeds that which is required by the device(s) that you will be supplying...
Thanks for the link to the sampler from moleculo. I wonder if he recalls where he picked up the small case. It is a perfect fit for the task at hand. I read through to the link from Captain Kilowatt, regarding Harold Kinley's article that described the modified T connector sampler. You learn...
......and those CMC's are what is allowing you to sample the rf in the first place. If you're not interested in absolute magnitude of the signal and merely looking for noise or distortion, then I would not worry about it too much. Otherwise try a different sampling method. Good luck.
Dave
I am going to crawfish just a little here. Before possibly performing any of my previous suggestions, I would insure that all of your test equipment, radio under test and power supplies are all supplied by the same AC outlet. This helps to reduce possibility of ground loops. You might also try...
You may have better results using an unbalanced method. Try using a 10X probe with capacitive coupling via a .01 uF ceramic cap. Try with or without probe ground attached to radio chassis ground.
Otherwise take a look at the link below and the description of an inductive RF sampler circuit...
Radioman if you have not already done so, I would try running either of your transceivers on DC from a battery and kill your AC main breaker. That would definitely eliminate your home as the source. That is some stout rfi for sure.
Radioman it appears to me that you have eliminated your home as a source of the interference, if your friend turned off all off your breakers in succession. It is possible that one of your neighbors could have placed a new electronic device online, or it could be caused by faulty power pole...
Yep, there are always going to be those who will lessen the pleasure of others. The one I'm tired of hearing is the old man doing the "day after day after day" routine. It's just generally a good idea to QSY away from 38 lsb, especially when it is very busy.
Sorry, but in regard to my previous post regarding the large electrolytic caps, I failed to mention that I paid little attention to the time it takes for the dc to bleed off the power supply output. It was not an issue in my case, because it happens within several minutes. There may even be a...
And although these large value electrolytics will not filter any rf noise, they will however act as buffer to the voltage drop on peak instantaneous current excursions in your rf amplifier, just as they do for the high power audio systems as noted above. I bought a lesser quality 0.5 Farad unit...
Correction. I should have said type 31 material would be better than 43 at 27 MHz, as opposed to 61 for reducing common-mode currents. If you look at the tables in the Fair-Rite catalog online, you will see that type 31 is good from 1-300 MHz, and type 43 for 25-300 Mhz. The 43 is commonly...
It would certainly be a good idea to make your antenna pole or tower ground a priority issue. This is not only good standard radio practice, but it can make a big difference in the magnitude of surge current that can occur and enter your home in the event of a lighting strike. Trust me, I've...
In reference to the Maxwell article, even ground wires can radiate if they are not kept below 1/4 wl to achieve a very low reactance rf ground. The rf ground, if established, would then be a much easier path, compared to the high impedance that would be encountered back to the ac service through...
I noticed your cmc thread and will certainly check it out. I have currently been reading thru the 44+ pages of the New Sirio Gain Master thread. Last night I got side tracked by Booty Monsters old Sigma IV thread, which led to a very lengthy thread on eham. I've known about some of this material...
No-Ox-Id is a great product that I have used on occasion for resolving surface contact issues in connectors. For antennas, Burndy Penetrox A, or NSI OX-8 is a much better choice for aluminum to aluminum or aluminum to copper connections. As far as paint is concerned, try to choose a paint with...
And I also wanted to tell you that I basically feel the same way about on-the-air antenna comparisons. As I'm sure you are aware, gain figures have been so severely inflated or either misunderstood by some manufacturers and/or users that they can be meaningless at times. Even though we can use a...
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