Hello anyone have any suggestions on how to measure retun loss on 1 5/8 fxl-1873 50 ohm hardline when only 1 end accessible, velocity factor is around 88% using a nano vna Thanks Terry N8JX

I got tired of trying to keep track of all those little SMA calibration standards and adapters that I keep with my NanoVNA, so I made a thing! It's a small pcb that uses common 1/4" wide edge mount SMA connectors to keep the calibration standards and adapters neatly organized. A couple of pics are attached. A PCB can be ordered directly from OshPark if you're interested: https://oshpark.com/shared_projects/CAtOPKYg 73, AA7US

* * * * *latest update de k3eui Barry END-FED wire extension to 140 feet* * * *new QTH: Kennett Square PA (SW of Phila)* * * *I waited for a cooler day to extend my 70 ft end-fed (worked well on 40/20m) out to the full length of _140 feet_.* *It is fed via a 49:1 UNUN (MyAntenna) with a 33 ft counterpoise, with 50 ft of RG8X.* *RF Choke before coax enters the shack for RFI prevention. * * * *My goal: be able to use this on three bands: 160/80/40 in the digi part of each band.* *So I left it a bit "long" at about _140 ft_ (most cut this to 130-135 ft for phone part of bands)* * * *I am ready to try this out on the Sunday NBEMS nets:* * PaNBEMS at 0730 hr on 3583 kHz (Thor 22)* * NJNBEMS at 0900 hr on 3582 kHz (Thor 22)* * * *It is oriented East-West but low to the ground, so likely has no directional gain/loss.* *We'll see tomorrow morning.* * * *Here is the Nano VNA plot of SWR and Return Loss dB (plotted as a negative value)* *SWR is below 2:1 where I will operate with sound card modes.* *Looks like I might be able to improve it just a bit by cutting 1 to 2 ft off the far end.* * * *note: Return Loss about /_-3 dB_/ where the antenna is /_not_/ a multiple 1/2 wave (resonant) * *which may show UNUN loss or coax loss - but I'm not worried about this loss on these bands. * * * *de k3eui* *July 20*

The file saved after taking a screenshot of the SD card was blank when I copied it to my computer and opened it.

Hello Folks, Saw couple topics related with "USB device (device descriptor request failed)" on this group, at least two of them - similar to what I'm facing right now - seems to have no solution. When trying to put my NanoVNA H4 in DFU mode (click the wheel + power on), Windows 10 would show it under device manager as "USB device (device descriptor request failed)". Other than trying to upgrade firmware, the device seems to be working properly. Tried unsuccessfully couple solutions found here and there: - Right clicked "USB device (device descriptor request failed)" and point to installation folders of "DfuSe Demo V3.0.6" and "STM32 Cube Programmer 2.16.0", trying to discover DFU drivers - Excluded "USB device (device descriptor request failed)" from USB power saving - Entered DFU from NanoVNA H4 advanced configuration menu; entered DFU mode by shunting the BOOT0 and the adjacent VDD pins - Also tried on macOS and Linux... The NanoVNA H4 seems to have no problem entering DFU using one of available modes to do so, but somehow, once in that mode, wrongly presenting himself to OS. I believe during the last firmware upgrade some part of the NanoVNA H4 has been wiped / wrongly flashed etc..., ruining the USB flashing interface. While further googling this issue, I found "nanoVNA-H – recovery" (https://owenduffy.net/blog/?p=16699) that describes a procedure to flash NanoVNA H, using SWD interface. Such procedure consist in connecting an external STM32 programer (STLINK-V3SET) to the pins SWDIO, SWCLK, GND and NRST present in both NanoVNA H and H4. Did anyone tried recovering NanoVNA H/H4 from this issue using STM32 programmer? (sorry for the long post, just want to be clear on my ask) Regards, Anaxi

* * *My goal: build a simple _inexpensive_ vertical for LOW-angle take-off for the 30m thru 10m bands* *(I already have a 40m NVIS low horizontal wire for NBEMS nets) * * * *I began with a 30 yr old Cushcraft A10 (halfwave on 10m band only) all aluminum vertical and took out the 10m parallel matching circuit LC * *and replaced it with a Palomar Engineering 9:1 UNUN (the bullet model).* *I had no idea what kind of impedance this 18 ft vertical would show on 30m thru 10m.* *But it was on hand after 30 yr as a single band 10m antenna, had no expensive traps for each band (like the 5BTV Hustler), and not all that imposing to folks in my apartment complex.* *It kind of looks like a tall fishing pole.* *I may put a bird house or bird feeder near the top to disguise it a bit. * *It is mounted on a 4 ft mast to get it off the ground a few feet.* * * ** * * *Once it showed low SWR on these bands, I assumed that was a "good start".* *And yes, I measured the SWR with the Nano VNA and SAVER software, from the shack (at the end of 50 ft RG213 and a choke). * *I can certainly now tune this up on 30m thru 10m with a SWR of about 2:1 in the shack.* *Shack tuner cleans up the rest to a 1:1 match for the rig to see.* *Running about 25 watts at the moment, and tried FT8 (heard no PSK31, MFSK, olivia or THOR on 17m) * *Whether it works (or not) is not a certainty shown by the low SWR test, so we will see who actually hears me using PSK reporter.* * * *I just added a second 30 ft radial on the ground (good advice) and this is the new Nano VNA plots for SWR and RETURN LOSS.* *Of course there are likely losses in the 9:1 UNUN and 50 ft coax since the RETURN LOSS minimum is about 7 dB and maximum about 17 dB where SWR is lowest. * *Yes, I am plotting RETURN LOSS as a negative value to have the same shape as the SWR graph. * * * *de k3eui Barry* *near Phila PA USA* *Here are the stations who hear me (10 AM July 17) on 17m band (18.1 MHz) with FT8 * *I am from the Phila PA USA region.* *Not bad for a 30 yr old 10m vertical repurposed for six bands at just the cost of one 9:1 UNUN* *Maybe I could have wound my own 9:1 and saved some $* * *

* OOOPS* *What happens when an end-fed, one-halfwave wire is a bit too long?* * * *I recently put up only half of my 80m (140 ft) end-fed MyAntenna wire (about 70 ft) and it shows* *the typical RETURN LOSS (dB) indicating low SWR at multiples of the fundamental just below the 40m band.* *This model uses a 49:1 UNUN and a 30 ft counterpoise.* *Fed with 50 ft RG213 and 10 ft section of RG8X. * * * *I think if I shorten it about 3-4 ft the dips will land right where I want them - in the digi part of 40/20/10m.* *It also has a very low SWR around 50 MHz (the 7th harmonic of 7 MHz) - super for 6 meter FT8.* * * *But I plan to now stretch it out the complete 140 ft to get 80m - that means crawling into the woods on a steep hill. * *de k3eui* * *

*I have been struggling to get HF antennas at Crosslands (Kennett Square) due to the constraints here (like at most communities).* *I have an end-fed 60 ft wire low to ground for NVIS that is working well on 40m but I wanted something that would put out a low-angle DX signal* *on 30m thru 10 meters. * * * *I tried setting up a 18 ft Cushcraft (aluminum tubing) vertical antenna (normally tuned to 20m single band) but fed via a 9:1 Palomar UNUN* *and 50 ft or RG213 with a choke at the shack to help knock down RFI in the shack. * *Then attached (so far) one 33 ft radial (I had used for 40m) and lo and behold - it works - /fairly low SWR on SIX BANDS from 30m thru 10m with no traps /* *let's now see if I can get any QSO's on these bands -* *de k3eui barry*

I bought a Nanovna-H from China. The language was Chinese. To make it English I upgrade the firmware. Before updating the firmware the display was ok and horizontal. But after the update, the display is having some issues. It turns into vertical. I can't see the menu also. I tried to search for fixes over the internet but found none that would solve my issue. Has anyone faced the same issue and resolved it? Can anyone help me to solve this issue?