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Re: look what I found at Goodwill
Nice find! I still have my dad's Post slide rule AND the leather belt holster AND the hard cover? instruction book. I used it with a $45 four function calculator in my undergrad physics class in the early 70's.
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KE4NBB Ted On Thu, Aug 11, 2022 at 6:27, David Wilcox K8WPE via groups.io<Djwilcox01@...> wrote: What kind of battery does it use, and where do you put it in? I hope they took the battery out years ago or it will be all corroded. Ha!? Wish I had kept mine but being a poor student needed cash all the time and sold whatever I wouldn¡¯t need in the future. Dave K8WPE David J. Wilcox¡¯s iPad On Aug 10, 2022, at 5:55 PM, Martin Glazer <mglazer2014@...> wrote: |
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Re: look what I found at Goodwill
There is an excellent group, [email protected], which covers the history, uses and collecting of slide rules; a great resource for small time collectors like me and for serious collectors and users. Lots of discussions of physics, electronics, mechanics applications. I have a Cleveland Electronics rule with all the equations on the back, but I didn't take it to the Extra exam!
72/73 de k1qed, ?bob.c ? ? ? ? qrp 4evr! |
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Re: look what I found at Goodwill
This is the second thread about slide rules in the past month. Here is the link to the previous thread. /g/nanovna-users/message/29044
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Re: Testing X polarity Antenna switch
I am not at home at the moment to investigate the antenna. I should have paid more attention when selecting antennas. All the parasitic elements are in and X config but now that you mention it the driven elememt may not be X. I do have the wimo rhcp harness if the relays won't work. Rotating the boom 90 degs should not be difficult.
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Thanks Glenn VE9GJ On August 12, 2022 8:10:49 PM ADT, "Dave W6OQ via groups.io" <david.hostetler@...> wrote:
Well I considered that rotating it 45 degrees would fix it, but is it simple enough? The antenna boom is square and I am not sure how that will be easily attached to the mast or other mount system. |
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Re: Testing X polarity Antenna switch
Yes, you simply rotate the Antenne by 45 degrees and it will worked fine.
Regards Matthias www.dd1us.de -------- Urspr¨¹ngliche Nachricht -------- Von: "Dave W6OQ via groups.io" <david.hostetler@...> Datum: 12.08.22 23:43 (GMT+01:00) An: [email protected] Betreff: Re: [nanovna-users] Testing X polarity Antenna switch Glenn: I reviewed the antenna that you linked to (WMO-18011) and I am pretty sure that it isn't compatible with the polarization switch that you linked to. The antenna has an unusual feed element that gives H and V output directly, without having to phase the driving elements to achieve H or V linear polarization. This polarization switch with this antenna will produce +45 degree, -45 degree, RHCP and LHCP. |
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Re: Testing X polarity Antenna switch
Glenn:
I reviewed the antenna that you linked to (WMO-18011) and I am pretty sure that it isn't compatible with the polarization switch that you linked to. The antenna has an unusual feed element that gives H and V output directly, without having to phase the driving elements to achieve H or V linear polarization. This polarization switch with this antenna will produce +45 degree, -45 degree, RHCP and LHCP. |
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Re: nanovna-saver crashing when saving calibration on Ubuntu
That was what I suspected however as a regular user I can open and view the file in the error message. I am sure it is a permission thing. Have to keep looking.
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Thanks Glenn VE9GJ On 2022-08-12 14:35, Tim Dawson wrote:
Then check permissions on the paths in the error for a start. It |
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Re: nanovna-saver crashing when saving calibration on Ubuntu
Then check permissions on the paths in the error for a start. It sounds like something does not have permissions to a non-root user.
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On August 12, 2022 12:29:21 PM CDT, Glenn VE9GJ <ve9gj@...> wrote:
Will do. --
Sent from my Android device with K-9 Mail. Please excuse my brevity. |
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Re: nanovna-saver crashing when saving calibration on Ubuntu
Will do.
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I discovered it works OK when run as root. 73 Glenn VE9GJ On 2022-08-12 14:27, Dragan Milivojevic wrote:
Open a new issue on their github if it wasn't reported before. |
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Re: nanovna-saver crashing when saving calibration on Ubuntu
Open a new issue on their github if it wasn't reported before.
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On Fri, 12 Aug 2022 at 18:26, Glenn VE9GJ <ve9gj@...> wrote:
nanovna-saver v0.4.0 binary release |
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nanovna-saver crashing when saving calibration on Ubuntu
nanovna-saver v0.4.0 binary release
OS Ubuntu 22.04 64bit After doing a calibration in nanovna-saver I can apply it OK and then when attempting to save the calibration it will cause nanovna-saver to crash. error: **** (nanovna-saver:123904): Gtk-WARNING **: 12:33:33.004: Could not load a pixbuf from icon theme. This may indicate that pixbuf loaders or the mime database could not be found. ** Gtk:ERROR:../../../../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /usr/share/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3) Bail out! Gtk:ERROR:../../../../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /usr/share/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3) Aborted (core dumped) The file /usr/share/icons/Yaru/16x16/status/image-missing.png does exist and displays OK for a regular user. Any suggestions? TIA Glenn VE9GJ |
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Re: Testing X polarity Antenna switch
Hi Dave
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Thanks for the input. Yes you are correct, this switch does have both "antennas" configured as an X and they are both always connected. The switch is based on the work of I8CVS. I should have included the link in y original post. The antennas I am using are the Wimo X-quad so both antennas are offset by zero degrees. This is very much a learning exercise for myself. I will need to obtain some more BNC to sma jumpers or adaptors to do some more testing. I also started using nanovna-saver and getting some crashes but that will be a separate post. 73 Glenn VE9GJ On 2022-08-12 03:32, Dave W6OQ via groups.io wrote:
So this switch actually has BOTH antennas connected ALL the time for |
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Re: look what I found at Goodwill
I was an organic chemistry major and graduated with my BS in the late-60s long before electronic calculators. (We had honking-big Marchant mechanical calculators in a room somewhere in the building and they were almost always occupied at most convenient hours and the next best calculator was the slide rule.)
I had an organic quant prof who expected us to be able to hold our writing instrument in one hand and hold a slide rule in the other and do the math with his exams timed with that capability in mind without ever putting either down.. He even had sessions after his classes instructing in the proper use of the "slip-stick" and ways to achieve greater precision which he expected to be at least 2 significant digits approaching 3 which was about the width of the scribes on the rule. In fact, I believe he claimed there was some relationship between the precision of those scribes and the capability of the slide rule but I can't recall his rule. Of course, he advocated a circular slide rule as the better choice over a linear slip-stick as it was far more compact for the precision. I have a small Fullerton 1450, 85mm circular in my desk and a slightly larger one in my go-bag which I keep against the time when the revolution starts. I had a K&E about 2.5 inches wide, a wooden - not bamboo - slide rule that got stuck when humidity was high, a couple of Dietzgens, Pickets, etc. I wish I had any one of those to show my sons and their kids - they wouldn't believe how such arcane devices landed us where we are now. Of course, the E6b is nothing but a special purpose circular slide rule which scares many student and novice pilots but I felt quite comfortable with it during pilot training and still keep one handy in the cockpit. So ends my paean to the lowly but powerful mechanism of the "bad old days". |
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Re: Testing X polarity Antenna switch
So this switch actually has BOTH antennas connected ALL the time for ALL modes, so the nominal 3 dB loss from the input to each antenna is present at all times. Be sure to terminate the antenna connector not being measured for good results. Their assumption is that the crossed antennas are mounted in an X with respect to the horizon rather than a plus (+). On the website you linked they have VNA measurements for each mode and both antennas. If the driven elements are located at the same point on the boom, the feedlines should be the same length, but the length isn't critical. If they are offset (which is common), you will need to adjust the feed line to one of the antennas so the phase matches the at the switch antenna connectors.
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Re: Testing X polarity Antenna switch
On 2022-08-11 21:25, Jim Lux wrote:
On 8/11/22 12:13 PM, Glenn VE9GJ wrote:Thanks for the great explanation Jim! I think I understand what to do now as your instructions make sense to me.?I recently finished building some Sat antenna polarity switches. (2M and 70CM)This unit takes a single feedline from the Tx/Rx to two antenna ports. 73 Glenn VE9GJ |
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