You dont have a ground plane to go with the antenna such as the radio itself acts as a ground plane for those antennas as well as your body. There is my 3 cents.
Looking forward to your videos when you have time. I have enjoyed them for a long time. How about explaining how to configure the NanoNVA for checking antennas?
You need to tune the antenna while connected to a HT with the other half of the antenna (HT metal frame/ground plane). While your at it, have it in your hand and in font of your face as if you were talking in it. Now you will know what the SWR is while transmitting in a real life scenario. In a hand, in a lab and connected to a 50 ohm coax does not seem like the way these antenna should be tuned for or are even used for. The finals in these HTs can handle high SWR at even higher duty cycle and power output.
I love the nanovna as well as the tinysa but both need some kind of help staying put- so aggravating having them chase you around the bench,- hope the new job is working out
Sending my sympathy your way. My father passed last September. The grieving won't ever go away, but it will become "easier", for lack of better words. As long as there are good memories, she will continue to live on in your heart. I had a Comet SH-55 (similar to your knockoff and real 771). Must've been a counterfeit though because it didn't work at all and Comet is known for good antenna's. It kind of received, but didn't transmit at all unless the receiving party was within 25ft. But I digress, I have two favorite antennas for my HT's: 1. Nagoya NA-701C. It's an 8in whip tuned to 155mhz and 455mhz. It works great on 2m, 70cm, MURS and GMRS. 2. Maldol AH-209. It's a 3in 1/4w "springy" rubber ducky tuned to 2m/70cm. This one is absolutely fantastic for its size, but almost impossible to find. Comet makes a similar one to it the SMA-209. I can't speak to it's performance however, as I've never owned one.
My god, I find the coolest and easiest to understand electronics teacher and the you tube bottom falls out? Sh*t! Best of luck to you sir, sorry for your losses. I would tune into a video on how you tube financials work as I believe you would be a great explainer.
Neat radio! Can it be unlocked and do GMRS/MURS? Asking for a friend. Kind of a bummer it doesn't have the Motorola Multi-pin connector. But kenwood compatibility I guess.
Shouldn't these aerials require at least a small amount of ground plane to obtain the best impedance match. When used with a transceiver, the body of the radio and its associated circuit board will provide a ground. Do these aerials come with a data sheet that specifies a 50 ohm match at the connector? It might be worth testing with a connector fitted to a metal box, or soldered to a handheld size sheet of PCB. I doubt that these 1/4 wave aerials contain any matching components, such as a tapped coil, to correct for the lack of a ground. If I am correct, the cable linking the VNA to aerial is acting as the earth. Changing its like length will have an effect on the vswr over the bandwidth.
The antenna needs to be held in front of your face as if using a "hand-held" radio. The human body forms part of the counterpoise. The sweeps will still be bad (no getting away from physics) but they will be better than holding the antenna at arms length. At least I think that is what was being done (it was off camera).
@@-vermin- if you consider the length of the body of the handheld, the earth plane of the circuit board will act as the earth. A long time ago, late 1970s , I owned a crystal controlled Pye PF70 handheld transceiver, tuned to operate on the VHF amateur radio band. This had a metal, 3 channel, crystal crystal selection switch on the front, below the speaker. The output power was close to 5 watts on a full charged battery A T type connector was used to connect the helical aerial. One of the hazards of using this radio, was suffering from apparent cold sores. These were actually RF burns produced by the lips coming in contact with the channel switch. I discovered that it was possible to draw RF sparks off this exposed metal part, it being connected to the chassis of the transceiver, such was the poor matching onto the helical aerial.
Shame there wasn't a plot covering the range approx 100 - 500MHz and it would be clearer what's happening. Somewhere in the Internet are some photos contrasting what's in a genuine Taiwanese Nagoya 771 (a coil tapped with capacitors and a matching copper sleeve round the base of the whip) and the PRC fakes (a spring and a double thickness of shrink-fit tubing to resemble the matching sleeve). Because the fakes lack the matching components they just function like a quarter-wave at about 190 MHz (as you'd predict from a straight whip of about 36cms). If they give a vaguely acceptable SWR at 70cms, that's pure fluke. :-( I did have a couple of those fake 771s, but when I found out what rubbish they were, I cut them down to resonate at 70cms using my nanoVNA and bolt cutters and use them for UHF only. ☺ I usually found that the "official" antennas supplied with Baofeng, Woxun etc radios did, in fact, work exactly how they should with a good SWR in the right places. Ironically, my best antenna is an OBVIOUS fake - a ridiculously cheap one claiming to be a Diamond RH771: the VNA plot showed it resonating perfectly on both 2m and 70cms. A fake, but obviously a good one! ☺
indoor tests are not reliable, VSWR is not everything, it would be good to do a test of S12 (S21) with the same antenna or a reference antenna with know gain.
Doing S12 or S21 on an antenna? How would you do that? S11 gives more information than just the SWR, but the way you measure is even more important. Connecting the antenna directly to the nanoVNA is probably the simplest. Then you shoulg hold the VNA in your hand, with no cables connected. Also, one can make a mock up handheld, with a choke inside, to prevent common mode current. Then the VNA may be connected to a PC. Measuring radiation pattern and gain is a different story. Then you can measure S21 between the test antenna and a reference antenna, or vice versa.
It isn't a very reliable way to test HT antennas, because when you hold an HT, you are part of the antenna. Holding the NanoVNA doesn't replicate that.
You do what you need to do. We'll still be here.
Agreed
No need to apologise, we are here and we enjoy your content 😊
I love this channel regardless of the upload speed. I wish you luck on finding a great job.
God Bless Paul.
You dont have a ground plane to go with the antenna such as the radio itself acts as a ground plane for those antennas as well as your body. There is my 3 cents.
You are correct
No need to apologize. You are great sir! Thank you
I heard this quote a long time ago, Paul..."Change is often desirable, frequently necessary, and always inevitable".
Indeed
Sorry for your loss Paul, take care and take the time you need. No need to apologize at all.
Looking forward to your videos when you have time. I have enjoyed them for a long time. How about explaining how to configure the NanoNVA for checking antennas?
You need to tune the antenna while connected to a HT with the other half of the antenna (HT metal frame/ground plane). While your at it, have it in your hand and in font of your face as if you were talking in it. Now you will know what the SWR is while transmitting in a real life scenario. In a hand, in a lab and connected to a 50 ohm coax does not seem like the way these antenna should be tuned for or are even used for. The finals in these HTs can handle high SWR at even higher duty cycle and power output.
Sorry to hear the bad news, you just do what you need to do..
I love the nanovna as well as the tinysa but both need some kind of help staying put- so aggravating having them chase you around the bench,- hope the new job is working out
Sending my sympathy your way. My father passed last September. The grieving won't ever go away, but it will become "easier", for lack of better words. As long as there are good memories, she will continue to live on in your heart.
I had a Comet SH-55 (similar to your knockoff and real 771). Must've been a counterfeit though because it didn't work at all and Comet is known for good antenna's. It kind of received, but didn't transmit at all unless the receiving party was within 25ft.
But I digress, I have two favorite antennas for my HT's:
1. Nagoya NA-701C. It's an 8in whip tuned to 155mhz and 455mhz. It works great on 2m, 70cm, MURS and GMRS.
2. Maldol AH-209. It's a 3in 1/4w "springy" rubber ducky tuned to 2m/70cm. This one is absolutely fantastic for its size, but almost impossible to find. Comet makes a similar one to it the SMA-209. I can't speak to it's performance however, as I've never owned one.
Thanks. It's rough. Since 2018 I've lost my dad, mom, godfather, uncle, aunt, and now godmother. I've got one aunt left.
Sorry for your loss. Also, sorry you have to go back to work.
My god, I find the coolest and easiest to understand electronics teacher and the you tube bottom falls out? Sh*t! Best of luck to you sir, sorry for your losses. I would tune into a video on how you tube financials work as I believe you would be a great explainer.
Sorry to hear Paul. Good luck looking for work. We can wait for your gems of knowledge.
Neat radio! Can it be unlocked and do GMRS/MURS? Asking for a friend. Kind of a bummer it doesn't have the Motorola Multi-pin connector. But kenwood compatibility I guess.
I have heard that it can made to do such things.
blew my mind at the with that price thats not bad easily obtainable for a begginner. also glad to see i video
It's a step up from the usual UV5R
Shouldn't these aerials require at least a small amount of ground plane to obtain the best impedance match. When used with a transceiver, the body of the radio and its associated circuit board will provide a ground. Do these aerials come with a data sheet that specifies a 50 ohm match at the connector? It might be worth testing with a connector fitted to a metal box, or soldered to a handheld size sheet of PCB.
I doubt that these 1/4 wave aerials contain any matching components, such as a tapped coil, to correct for the lack of a ground. If I am correct, the cable linking the VNA to aerial is acting as the earth. Changing its like length will have an effect on the vswr over the bandwidth.
The antenna needs to be held in front of your face as if using a "hand-held" radio. The human body forms part of the counterpoise. The sweeps will still be bad (no getting away from physics) but they will be better than holding the antenna at arms length. At least I think that is what was being done (it was off camera).
@@-vermin- if you consider the length of the body of the handheld, the earth plane of the circuit board will act as the earth. A long time ago, late 1970s , I owned a crystal controlled Pye PF70 handheld transceiver, tuned to operate on the VHF amateur radio band. This had a metal, 3 channel, crystal crystal selection switch on the front, below the speaker.
The output power was close to 5 watts on a full charged battery A T type connector was used to connect the helical aerial. One of the hazards of using this radio, was suffering from apparent cold sores. These were actually RF burns produced by the lips coming in contact with the channel switch. I discovered that it was possible to draw RF sparks off this exposed metal part, it being connected to the chassis of the transceiver, such was the poor matching onto the helical aerial.
Try holding the antenna in front of your face as if using a hand-held. The human body forms part of the counterpoise.
So does the metal frame and ground plane of the HT.
you so need to get Nanosaver going on the pc to use with the nanovna, makes it so much easier to present on screen.
Nanosaver? Thanks! I'll have to check that out.
Theres an antenna analyzer function built in also. Using that lil wheel is like, if-all-else-fails hahahs@@learnelectronics
Thanks for the share and information sir🙏🏼♾️
No worries Paul. Family is first. Videos aren't going anywhere. ☮️
Hey Paul sorry for your loss. You do good work and wish you the best. I appreciate each upload you can make take care KN4QKF
Shame there wasn't a plot covering the range approx 100 - 500MHz and it would be clearer what's happening.
Somewhere in the Internet are some photos contrasting what's in a genuine Taiwanese Nagoya 771 (a coil tapped with capacitors and a matching copper sleeve round the base of the whip) and the PRC fakes (a spring and a double thickness of shrink-fit tubing to resemble the matching sleeve).
Because the fakes lack the matching components they just function like a quarter-wave at about 190 MHz (as you'd predict from a straight whip of about 36cms). If they give a vaguely acceptable SWR at 70cms, that's pure fluke. :-(
I did have a couple of those fake 771s, but when I found out what rubbish they were, I cut them down to resonate at 70cms using my nanoVNA and bolt cutters and use them for UHF only. ☺
I usually found that the "official" antennas supplied with Baofeng, Woxun etc radios did, in fact, work exactly how they should with a good SWR in the right places.
Ironically, my best antenna is an OBVIOUS fake - a ridiculously cheap one claiming to be a Diamond RH771: the VNA plot showed it resonating perfectly on both 2m and 70cms. A fake, but obviously a good one! ☺
I think you test it not holding it, that’s why it jumps around.
indoor tests are not reliable, VSWR is not everything, it would be good to do a test of S12 (S21) with the same antenna or a reference antenna with know gain.
Doing S12 or S21 on an antenna? How would you do that? S11 gives more information than just the SWR, but the way you measure is even more important. Connecting the antenna directly to the nanoVNA is probably the simplest. Then you shoulg hold the VNA in your hand, with no cables connected. Also, one can make a mock up handheld, with a choke inside, to prevent common mode current. Then the VNA may be connected to a PC.
Measuring radiation pattern and gain is a different story. Then you can measure S21 between the test antenna and a reference antenna, or vice versa.
It isn't a very reliable way to test HT antennas, because when you hold an HT, you are part of the antenna. Holding the NanoVNA doesn't replicate that.
You should still learn how to record displays.