While a person experienced in phasing system design can work around it, that will cause problems. The simple "equal current" feed will no longer work with base fed radiators electrically longer than
Bill and All, I agree with everything you said Bill (except CW bandwidth, hi hi). I especially agree that Leif's weak signal work only applies to EME or VHF use, not to typical 160 conditions. The po
Hi Jason If you don't have a balun and happen to have a bad combination of feedline shield electrical length, there can be quite a bit of difference. Which side should be where would be random luck.
Better watch the current required and the relay sequencing or timing. Vacuum relays often use fairly low resistance coils, and generally surplus relays are 24VDC or higher voltage. Adding a backpuls
Having designed the SB1000 and owning two 706's, I'd never connect the 706 to the SB1000 without an interface buffer of some type. The IC706 has the most sensitive to damage keying system of any rad
hence Not really. While the normal peak operating voltage with the tank properly tuned into a load is less than the dc plate voltage of the amp, the voltage across the capacitors can vary a great de
With a front end problem, the non-linear artifact is almost always easily identifiable spurious signals. All sorts of odd signals (like mixes of BC stations) are present that "aren't really there" w
can my Hi Tony, Phase noise and dynamic range/overload problems have any effect in a test like Earl's. We won't hear phase noise unless a strong close by signal is present, just as we won't hear ove
Group delay changes should be as small as possible within low attenuation area of the filter because that is the only area that contributes to significant desired signal or significant noise, while
I wasn't suggesting any problem specific to the Orion. I was suggesting general causes of different ability to receive noise floor signals, which certainly exists. Poor weak signal reception can be
The mod is a patch. Like all patches, it is less than perfect but it works well and has never caused any type of problem. It isn't even necessary to reverse bias the "switching" diode that isn't a s
Hi John and all, placed in the context of what distortions are really audible. It is well known in the field of psychoacoustics that the human auditory system is remarkably insensitive to phase disto
situations, distortion weak Hi John, A time-distortion of ~18mS in the keying sidebands of a CW signal certainly would have a large effect on the CW sound, as it would on any noise pulses. Other tha
Hi John, I'm sure we agree the upper and lower sidebands are what allow us to have a change in signal level. After all, the CW signal is actually amplitude modulation of a carrier. I don't see how I
Not a bad idea Kirk! We could record noise in a broadband digital recorder, and use that recording as a standard. In effect we would have a time machine, allowing us to compare receivers on differen
John, I wonder if the AEA VIA uses selective detectors (receivers), instead of broadband detectors. Selective detectors would allow easy phase measurement, and greatly reduce BCI. Right now the small
proportional current verticals, that this 160. John and all, As you point out, if the original element (NOT ground system, but element) is very lossy, the system would improve. However, very few peo
Barry, You can see a test of a ARR "one band preamp" using a GASFET on my web page. http://www.w8ji.com/pre-amplifiers.htm I'd be happy to measure any other common preamps anyone sends me after the D
meters??? The guaranteed performance range of a new properly calibrated slug is 2-30MHz, but they still work OK for amateur use at 1.8. Keep in mind the Bird meter is NOT perfect. The rated accuracy
50dB is a heap of TOI, so the amplifier must have some very beefy components. I haven't found an amp with an TOI of 50dB yet, except some post-mixer amps I built with VHF power FET transistors or hi