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Re: Firmware Differences
Hi Bob,
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You are correct about the type of resistors to use for measurements.? I mostly use BNC cables and devices, so I have built cal standards and measurement standards using BNC connectors as shown in the attachment.? I have tried to make my measurements as close to the reference plane as possible.? The resistors I use are 0805 film resistors and the capacitors are 0805 ceramic for the most part.? Since most of my work is done at HF, the calibration tolerances are not as tight as for VHF and UHF. Tom?? W0IVJ On 10/27/2022 6:00 AM, Bob Ecclestone VK2ZRE wrote:
Hello Tom, |
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Re: NanoVNA Saver - Display Smith Cart
On 10/28/22 8:41 AM, Charlie N2MHS via groups.io wrote:
I can see the SMith Chart on my H4. Is there a way to see it on my PC (W11 64bit)Doesn't Saver display it by default? Look at the button in lower left for "Display Settings..." Then, in the dialog, you can set the plot formats.. |
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On Fri, Oct 28, 2022 at 02:47 PM, Rudi wrote:
Well Rudi, the FW is organised as a tree in ui.c. The top menu is called "menu_top". This construction above searches all lines of ui.c (that I had read into the python variable ui and that I iterate all over again with "for line in ui:") for an entry that contains 'const menuitem_t menu_top[]' -> line 2071 of ui.c (line 2065 from DiSlord's src). "const menuitem_t menu_top[] = {" This python construct is called "formatted string" and it helps us poor C printf programmers to build nice strings also in python. I'm just searching for the definition of a menu block and then read all menu entries in this block until I encounter "MT_NONE" (=end of menu), if one entry is a submenu, I search for this submenu and read all entries, and if there's another submenu... you get the idea. So this line just searches for f'const menuitem_t {this_menu}[]', where the variable "this_menu" holds the name of the menu I'm currently checking, e.g. 'menu_top'. -> it's all no rocket science, years ago I used perl for this kind of parsing, but this language is to much "write only" for me, also because of TIMTOWTDI; python is more strict and can be understood also one year later (without massive commenting). BTW - how looks your part below the "SMITH" menu points? This is my 1st SMITH section: FORMAT S11 (REFL) LOGMAG PHASE DELAY SMITH LIN LOG Re + Im R + jX R + L/C G + jB G + L/C Rp + jXp Rp + L/C <- BACK Do you have the "Re + Im" entry or is it "REIM"? The s11smith menu structure in "ui.c" has only the token "MS_REIM" const menuitem_t menu_marker_s11smith[] = { { MT_ADV_CALLBACK, MS_LIN, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_LOG, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_REIM,"%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_RX, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_RLC, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_GB, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_GLC, "%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_RpXp,"%s", menu_marker_smith_acb }, { MT_ADV_CALLBACK, MS_RpLC,"%s", menu_marker_smith_acb }, { MT_NONE, 0, NULL, menu_back } // next-> menu_back }; The translation is in "plot.c", where I search all "[MS_...]" lines and extract the 1st string in double quotes, e.g. "Re + Im" for "MS_REIM". const marker_info_t marker_info_list[MS_END] = { // Type name format get real get imag [MS_LIN] = {"LIN", "%.2f %+.1f" S_DEGREE, linear, phase }, [MS_LOG] = {"LOG", "%.1f" S_dB " %+.1f" S_DEGREE, logmag, phase }, [MS_REIM] = {"Re + Im", "%F%+jF", real, imag }, [MS_RX] = {"R + jX", "%F%+jF" S_OHM, resistance, reactance }, [MS_RLC] = {"R + L/C", "%F" S_OHM " %F%c", resistance, reactance }, // use LC calc for imag [MS_GB] = {"G + jB", "%F%+jF" S_SIEMENS, conductance, susceptance }, [MS_GLC] = {"G + L/C", "%F" S_SIEMENS " %F%c", conductance, parallel_x }, // use LC calc for imag [MS_RpXp] = {"Rp + jXp", "%F%+jF" S_OHM, parallel_r, parallel_x }, [MS_RpLC] = {"Rp + L/C", "%F" S_OHM " %F%c", parallel_r, parallel_x }, // use LC calc for imag [MS_SHUNT_RX] = {"R+jX SHUNT", "%F%+jF" S_OHM, s21shunt_r, s21shunt_x }, [MS_SERIES_RX] = {"R+jX SERIES","%F%+jF" S_OHM, s21series_r, s21series_x }, }; But we can move this off-topic discussion to another point in order not to clutter this topic. -> |
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On Thu, Oct 27, 2022 at 07:47 PM, Rudi wrote:
Hi Rudi, I have no clue what goes wrong o your side, I copy/pasted the code here from the group and it works fine. (I suspected that the forum SW did some strange formatting) As a quick check add these two lines at line 26 (directly after the line with ' ms_dict[ key ] = val # put in dictionary') without any space to the left and show the output. print( ms_dict ) exit() Nevertheless the code with a safety check for you (and maybe other mac user) is now in my GitHub: Martin |
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Re: How to use my NanoVNA-H4 to test resonant frequency of a tower?
Don't know of any reason why it wouldn't work. However ... I'm guessing the wire vertical is NOT grounded at the base of it, but the tower is? That may have some effect on it. Maybe if you could test further up the tower? AM broadcast towers can be either series fed, where the base of the tower is insulated from ground and the tower is fed against ground at the base, or shunt fed, where the base of the tower is grounded and the tower is fed with a wire connected some distance up the tower from ground. Consider how this may affect your ability to measure the resonant frequency. And does the tower have guy wires? If so, I assume they are grounded, shunting to ground any potential resonances, or possibility creating a number of "sub-resonances."
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Ho-Ro
Jim Allyn - N7JA
Douglas Butler