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One thing that I did to make sure oranges were oranges and apples were apples.? I constructed a reactive termination for the analyzer.? Based on 10 MHz, I built up a series SMT structure of a 0603

Bill, I would suspect that all three of those meters are right, and that the antenna's behavior is changing according to what you connect to it! It's and OCF dipole, an antenna that is highly

Your question would be "is it a frequency measurement problem" or "is it a impedance measurement problem" - The first one could be answered by measuring a piece of coax that is shorted or open at the

I measured my 40M OCF Dipole with my NanoVNA-H4 and it shows that the minimum SWR of 1.68 is at 6.975 MHz. I had the loan of an MFJ-259C, and it shows the minimum SWR of 1.6 is at 7.14 MHz. I also

No, cost is very low, jut a few cents. During the design phase ESD strikes were applied directly at the input, it passed the tests. However, after my report of broken units, the designer (Gabriel)

That sounds great Mario! I'd love to see some write-up of what you found worked, and what didn't... anything that would make it easier for us also to get good test antennas.

I couldn't make even the small number of connections suggested with those little connectors. They died before. I put in parallel with each connector a pair of male-male pins used with IC sockets

Hi, the most likly reason, that the protection diode is not alredy present on the vna, is cost or possible problems against I good measure?

Hello-- Can anyone point me toward a Windows 7 version of the software application for the NWT70 analyzer? Thanks in advance, and 73-- Brad? AA1IP

There are versions of V2 with N and SMA connectors. V2 switches to si5351 for frequencies below 140MHz so that is correct. [email protected]> wrote:

Glad I caught this thread. I was thinking of getting a S-A-A-2 but if it has N connectors that would be problematic short term. I did hear though that the H4 uses harmonics above 300 Mhz or so, where

You're right.. I was looking at the wrong table..

Jim, You figure is far too low! 100pF per meter comes much closer to reality. Manfred

Ken, indeed you have to use the bidirectional type. Unidirectional ones conduct like any diode in the forward sense. They are pretty much like improved zener diodes. Bidirectional ones are two of them

Yes, that makes sense. The diode I used is a bi-directional type with a clamping voltage of 5.5V. Static charge build-up is limited to 5.5V which should be harmless. In my case I'm developing UHF RFID

Greetings all, Interesting discussion. When I Googled TVS (Transient Voltage Suppression) diode, it appears there are two varieties, unidirectional and bidirectional. I would assume a

Hi Dave The charge only accumulates if it is connected to an antenna that is not a DC short.? ?i.e.? long wire, gama matched Yagi, 1/4 wave vertical etc. Not a problem with a folded Dipole, loop,

A coaxial cable is a long cylindrical capacitor. Being by design low loss, it can accumulate and store a charge for quite some time. When connecting any longer piece of coaxial cable or other low-loss

I was measuring what turned out to be about 325 foot run of coax. About 200 feet of lmr400 and 125 feet of rg213. Think I will have to find some diodes to solder on the pcb. I don't think I have any

Soldering the diodes directly on the pcb is easy and you can never forget them... See pictures (follow the trace from connector to series capacitor to TVS diode to resistive pad (3 resistors). The