Notwithstanding your previous commentors, I believe you should attach the antenna directly to the meter and then hold it like you would hold the radio. Then your body will form the other half of the antenna, which is how they are intended to be used. If that's still bad, fair enough! 😊
I believe also part of the official testing procedure adds a head to the mix as you'd hold this near your mouth. This won't cure the fake here I promise!
As a lot of people already Said. Connect antennas directly to VNA, if it Is not possible use as short coax as you can And use that calibration set to calibrate VNA with this short coax, thats why you Have that set in box in the first place, otherwise it could be just calibrated in factory.
The extended lead will also effect the SWR and input impedance probably. I wouldn't use a too long table. Just make sure you do the test under repeatable defined situation ;-)
I cut one of these open and it was literally just a 36cm whip, no loading whatsoever so it is essentially a 1/2wl end fed on 70cm except it has no loading and is too short to be a 1/4wl on 2m. So no use on either band.
I had this non loaded version and cut it to 1/2wl on 430 worked well for me, increased range by a lot compared to the stock rubberduck and other "loaded" 1/4wl antennas I had
Want a good budget antenna? Get an Abbree tactical or other foldable antenna. They're ugly and unwieldy, but they are superb antennas. Don't know about the tri-band models, but they should work fine. I have a Nagoya NA-24J and the Abbree works just as well if not a little better. Thee 24J is far more difficult to copy, so you're more likely to get an original. Order from BTech or Amazon. Once you get a genuine Nagoya, you can easily check other antennas claiming to be Nagoyas by putting them side by side. The thing is, Nagoya antennas are well made, but they don't really extend one's range as much as you'd think. Looking at a graph is one thing; field testing's quite another. If it were me, I'd buy a Diamond Signal Stick or the 24J Nagoya.
i dont think having the antenna away from you would make much difference for swr. the antennas are made for hand held radio its designed to be used right next to you. your not holding the radio at arms length away when using it. i used my uv5r for the Australian 80 channel cb 476-477 mhz and the fake antenna did perform a little better than the standard one but not by great amounts. is testing the swr going to be accurate on such a little antenna they are not the same as a mobile car antenna or base station. more to the point before you tested the antennas with swr meter did they beform better? if they did i would'nt worry about the swr i dont think the standard antennas would perform any better on swr meter.
Yes, we did the same on PMR446 and the talk range increases greater than the standard UV5R/888s stock antenna etc. The VSWR results is still dubious and better to double check with analogue SWR meter such as SX600 etc.
I bought a Btech Nagoya 771 for an Australasian plan CB (476-7mhz) .... "120-900mhz" - Sweet!! ...but missed the bit where it says receiving only - I think it's optimized to 430 & suspect this is true of most general antennas out there - I also suspect some are being marketed for use outside of their working spec's too.... Anyway, so out of CB & GMRS range :) notarubicon did a vid on tuning antennas (trimming with wire cutters)... I don't know what frequency's you use most, but might this be an option to tweak the swr back into the park? I guess it might be academic if faith has been lost but might be an interesting exercise if the only other option is to bin the antennas..... ....Ah, & ground plane - wondering if you can use a metal plate as one, as is recommended for mk2 surecom SW102's???
Can you try the other OEM antenna(s)? The Baofeng one which tapers in and then continues fairly thinly to the top is supposed to be better than the "chunky" one, particularly on the amateur bands. I have both, myself, one of which came on each UV-5R I have, and I ordered another one of the "slim" ones as the chunky one, as tested in the first video, wasn't great.
Hi Fred, be VERY careful about the use of wrench on the SMA connectors! The key point is to tighten the SMAs properly. Not too loose and not too tight! Overtightening the connectors can cause the internals of the female connector to spread out, which can cause intermittent connections later on. Also be careful with how you're applying the torque at the connector. On there NanoVNAs, the connectors aren't installed in a very secure manner. They're usually just soldered on the pin side, and the other side of the connector has often no solder. This, together with use of a wrench, can cause the solder joints to crack, which can again lead to intermittent connections. There are proper SMA Torque Wrenches, which will automatically disengage when you reach the appropriate torque, but such a wrench alone could cost around 2-4 NanoVNAs, so obtaining a proper one might not be economically justified in this case.
Another good video Fred. Would it be worth doing a comparison test on an in line swr meter of a reputable make. I suggest something with a reasonable price like the Avair AV601. Something is telling me not to put too much faith in that VNA.. How about also checking a reliable antenna with the VNA like your amtron99.?
Prob a good idea Barry. Iam not going to get too much into these 2m/70cm antennas as really iam just using them to learn about the meter. What i really want to use the Nano for is building dipoles.
@@CB-RADIO-UK That's fare enough Fred but you need to know that the VNA is a reliable one otherwise you will be making dipoles that are way off resonance. That puts your other gear at risk. Maybe use it now to build a dipole then connect it to an in line swr meter that you know is reliable. I'm just not sure if I would be trusting that VNA tbh.👍
@@CB-RADIO-UK nice one for the heads up I will put the rubber ducky back on the other one... do you recommend me getting one of these fake nano.. it's in my watch list👍🏽
Seen a mod ... rat tail ground plane... Quick question Fred.... First ssb.... I've seen your videos championing Ss 6900 n What about the Alinco Dr 135 dx ( 10dx )
Yeah, I know this might seem a daft reason, but I think im gonna go for it, purely for its looks. Not sure if clarifier is "clicky" but the one plus I suppose is the programming cable has an external port.
Good morning Fred. Could you please try to use analogue SWR meter as a cross reference when testing the fake RH771 at f=446Mhz? TX at max 5W and see the reflected power. Very good video review of yours. Cheers!.
That does seem like a surprising result. Could you perhaps consider sacrificing an 888 by doing a practical test with one of these antennas? A simple "does it actually get fried" / range check should surely be able to confirm whether or not the SWR really is that bad 🤔
@@CB-RADIO-UK Thanks! I just watched that video, actually the fake 771 sounded a lot better than the standard antenna. So, something doesn't add up... This is intriguing, needs more investigation surely? Thanks for the interesting videos.
Well, rip. Wonder how practical would it be to homebrew handheld antennas because it doesn't make much sense to pay 20 bucks for an antenna for 10bucks bf-888s
Have you a way to see if the antenna uses the radio as a counterpoise?I would try a field strength meter and compare the fake to an genuine.2CM3284/KE5SRB.CHEERS from the States mate!
It is amazing how far off an antenna can be made on purpose. They must think that most radio operators would rather cheap god looking antennas rather than a performer.
Hi again Fred. Have you considered using a counterpoise or as it's sometime called "a Rat Tail". There are a few youtube Vids about these . With the supplied antennas you only really have one part of a half wave. If you add a counterpoise you are effectively completing the antenna. My friend has tried this on a handheld and got really excellent results. SWR came right down to a useable level and the signal went up by 3 S points. He told me the the counterpoise was 19.3 inches. Just an idea you might consider trying. Cheers & 73s Keith
What you are finding out is something I've seen for a long time , basically I ripped apart a cheap 'clone' and it had no loading , the closest it came to resonance was about 160Mhz. The best thing for these is trim them down to a UHF quarter wave!!! I jest you not. The main problem is that people buy these and convince themselves they're an improvement. they aren't. best antenna i've seen is the stock uv5R antenna for tune. great on 2m and 70cm! I guess 90% of the chinese antennas are crap , I have a big pile of them and theyre all shite! please people wake up and listen to this guy!!! I do have 1*771 which actually tunes on UHF and VHF. I also find 701's useless too!!!
John your prob right. When ive finished playing with it i will take these fakes apart on another video and give you a shout out. It will be interesting to see if there is any base loading.
These seem to be really bad fakes! I saw some other videos testing the (fake) NA 771 with much better results! There is also a video were they open up both a genuine and a fake antenna. The genuine had some matching circuitry in the bottom part with small coils and little caps! So i guess they do a quick manual matching for each antenna - resulting in the higher price tag. With my (probably fake NA 771 but for around 6 Eur) i managed to hear the ISS space station 3 times when it passed. I wasn't able with the orig. baofeng antenna (signal stick copy). Also try to use a counterpoise (wire attached for virtual ground) - this can really change a lot! Consider in real life your hand and body would act as a counterpoise for the antenna!
Go for it, I'd like to see! I've got one of these fake 771s and it does work better on the ham bands than the stock antenna, more on 2m than on 70cm (maybe not surprising because of the physical length). I tried ordering a Nano VNA but the seller asked me to cancel for some reason. Not got round to ordering another one.
It's never gonna measure right without a ground plane on the aerial to balance it out. Unless you are measuring a Slim Jim you must have a ground plane 😉 Any aerial without a decent ground will peg the meter as you found out with your loft aerial experiments 😊
Not convinced this test is accurate as the antenna has no ground plane, mounted on a car or handheld held in hand the result would be different. The mag mount alone is not enough. It has to be connected directly to ground through body or car, if not the ground plane/radials need tuning. I would check on car for best result, if only using on PMR you can cut the antenna to a quarter wave whip, the antenna is a 1/4 wave whip for 70cm with a trap/loading coil added. On 70cm the antenna only transmits from about 17.5cm of the antenna. On 2m it works as a top loaded antenna. 2e0deq.
Coincidentally, I was testing my NA-771's this afternoon before I saw your video, having also acquired a NanoVNA. I tested how others have suggested - attaching the antenna directly to the VNA (with a gender converter where necessary) and holding it like I would a radio. I'd (wrongly) assumed that Nagoya was a cheap (mainland) Chinese brand, and hadn't realised it was actually in Taiwan and rather better, hence worth faking. All three of my NA-771's were fake, but at least usable, and with roughly the same curve. Optimum SWR around 200MHz but usable (just - SWR
@@CB-RADIO-UK On second thoughts, only just about usable. ;-) One of them I only ever used on 70cms (a slightly unusual yellow one that I bought to match my slightly unusual yellow BF-888S) so I decided to cut it down. As predicted, it's a simple steel (?) cable, quarter wave resonant at around 200MHz. Why does it seem thicker towards the base? Simply 'cos there's a double thickness of shrinkfit. Anyway, I chopped it down with a bolt cutter, carefully removed and transferred the rubber titty off the end, and it works a treat. SWR better than 1.5:1 over both 70cms and PMR446. ☺ I'll carry on using the bogus Diamond - it's obviously fake, but it works fine - and keep the "Nagoyas" for emergencies only. Though I might treat myself to a genuine one from a UK source - my TYT handheld is opposite gender to my Baofengs and using a coupler is a bit fiddly.
I'll add that I checked the various stubby antennas that were supplied with the radios, and they were all fine. The optimum SWR tended to be a little lower - about 410 - 420MHz - but still well below 2:1 on 70cms / 446.
Notwithstanding your previous commentors, I believe you should attach the antenna directly to the meter and then hold it like you would hold the radio. Then your body will form the other half of the antenna, which is how they are intended to be used. If that's still bad, fair enough! 😊
Yes i could try that although it would be hard to record the reading on the camera. Yes a good video idea thanks.
Ordered a Male-Male connector so will try the test again when it arrives.
I believe also part of the official testing procedure adds a head to the mix as you'd hold this near your mouth. This won't cure the fake here I promise!
@@FB-np7cg Well i will do my best and try as close as i can. Should be interesting to test.
@@CB-RADIO-UK hold it facing away from you and put a camera on it? Be a pain in the neck, but you can read it that way.
Love your enthusiasm mate and how you explain stuff dead simply. Spot on, enjoyed this!
As a lot of people already Said.
Connect antennas directly to VNA, if it Is not possible use as short coax as you can And use that calibration set to calibrate VNA with this short coax, thats why you Have that set in box in the first place, otherwise it could be just calibrated in factory.
Thanks. A coupler is ordered and will follow up with the antenna connected to the Nano
Finally a VNA test of an antenna.... THANK YOU !
The extended lead will also effect the SWR and input impedance probably. I wouldn't use a too long table. Just make sure you do the test under repeatable defined situation ;-)
I cut one of these open and it was literally just a 36cm whip, no loading whatsoever so it is essentially a 1/2wl end fed on 70cm except it has no loading and is too short to be a 1/4wl on 2m. So no use on either band.
No loading at all ? Thats not good :-(
@@CB-RADIO-UK Literally nothing, just a bit of wire connected to the center of the SMA, cut it down to a 1/4 for 70 and it might be ok lol
I might cut one of mine down to look. Not really surprised though.
@@CB-RADIO-UK would be interesting if you make a video of it.
I had this non loaded version and cut it to 1/2wl on 430 worked well for me, increased range by a lot compared to the stock rubberduck and other "loaded" 1/4wl antennas I had
Food for thought Fred....it’s a learning curve mate.......Bob
Yep. Interseting stuff Bob
The SWR of my Nagoya NA-771 antenna I got at the swap meet is around 2.0:1 on both bands. That's livable.
Mine is 1.01 at 446 MHz and about 1.5 at 146 MHz. The Baofeng F8HP I got transmits 8W on UHF and 6.5W on VHF at max power. I'm swagging.
Fred in the shed is right i got my nano vna just yesterday i might make my own antenna for beofeng 12 gauge bare copper wire will work.
I got a Nagoya NA-771 antenna for $5 at a HAM swap meet and placed it on my RadioShack HTX-245. It works.
Is it possible to clip a little off the top and replace the cover. This would shift the tune point to a higher frequency.
Another quality report thank you, I would really like to see what is an upgrade for the UV-5R what can be sensibly purchased with reliable results...
Thanks for video....usfull as always...... can you shorten the antenna so the swr goes down?
Want a good budget antenna? Get an Abbree tactical or other foldable antenna. They're ugly and unwieldy, but they are superb antennas. Don't know about the tri-band models, but they should work fine. I have a Nagoya NA-24J and the Abbree works just as well if not a little better. Thee 24J is far more difficult to copy, so you're more likely to get an original. Order from BTech or Amazon. Once you get a genuine Nagoya, you can easily check other antennas claiming to be Nagoyas by putting them side by side.
The thing is, Nagoya antennas are well made, but they don't really extend one's range as much as you'd think. Looking at a graph is one thing; field testing's quite another. If it were me, I'd buy a Diamond Signal Stick or the 24J Nagoya.
i dont think having the antenna away from you would make much difference for swr. the antennas are made for hand held radio its designed to be used right next to you. your not holding the radio at arms length away when using it. i used my uv5r for the Australian 80 channel cb 476-477 mhz and the fake antenna did perform a little better than the standard one but not by great amounts.
is testing the swr going to be accurate on such a little antenna they are not the same as a mobile car antenna or base station. more to the point before you tested the antennas with swr meter did they beform better? if they did i would'nt worry about the swr i dont think the standard antennas would perform any better on swr meter.
Yes, we did the same on PMR446 and the talk range increases greater than the standard UV5R/888s stock antenna etc. The VSWR results is still dubious and better to double check with analogue SWR meter such as SX600 etc.
I bought a Btech Nagoya 771 for an Australasian plan CB (476-7mhz) .... "120-900mhz" - Sweet!!
...but missed the bit where it says receiving only - I think it's optimized to 430 & suspect this is true of most general antennas out there - I also suspect some are being marketed for use outside of their working spec's too....
Anyway, so out of CB & GMRS range :) notarubicon did a vid on tuning antennas (trimming with wire cutters)... I don't know what frequency's you use most, but might this be an option to tweak the swr back into the park? I guess it might be academic if faith has been lost but might be an interesting exercise if the only other option is to bin the antennas.....
....Ah, & ground plane - wondering if you can use a metal plate as one, as is recommended for mk2 surecom SW102's???
Interesting stuff Fred.. Have you tested any of the antennas that came with your radios using the same method ?
Yes pete on the first video.
Can you try the other OEM antenna(s)? The Baofeng one which tapers in and then continues fairly thinly to the top is supposed to be better than the "chunky" one, particularly on the amateur bands. I have both, myself, one of which came on each UV-5R I have, and I ordered another one of the "slim" ones as the chunky one, as tested in the first video, wasn't great.
the fake na-771 one i have got 20miles out on frs back in oct 2020 on uv5r.
Why, in the city, my uv5r 8W barely gives me 750mts of range???
Is because of the city or is the radio???
Prob reduced by buildings blocking signals. I can only get 1-2km in a built up area myself
Hi Fred, be VERY careful about the use of wrench on the SMA connectors!
The key point is to tighten the SMAs properly. Not too loose and not too tight! Overtightening the connectors can cause the internals of the female connector to spread out, which can cause intermittent connections later on.
Also be careful with how you're applying the torque at the connector. On there NanoVNAs, the connectors aren't installed in a very secure manner. They're usually just soldered on the pin side, and the other side of the connector has often no solder. This, together with use of a wrench, can cause the solder joints to crack, which can again lead to intermittent connections.
There are proper SMA Torque Wrenches, which will automatically disengage when you reach the appropriate torque, but such a wrench alone could cost around 2-4 NanoVNAs, so obtaining a proper one might not be economically justified in this case.
Yes good call. Thanks for the advice i will take it easy with the spanner
Have you done the same test using the original antenna from the UV5R? If so what results did you get?
Hi Rob. I cannot rem if i tested the stock antenna. If i did it will be in the nano videos.
Thanks for the video Fred.
Another good video Fred.
Would it be worth doing a comparison test on an in line swr meter of a reputable make. I suggest something with a reasonable price like the Avair AV601.
Something is telling me not to put too much faith in that VNA..
How about also checking a reliable antenna with the VNA like your amtron99.?
Prob a good idea Barry. Iam not going to get too much into these 2m/70cm antennas as really iam just using them to learn about the meter. What i really want to use the Nano for is building dipoles.
@@CB-RADIO-UK
That's fare enough Fred but you need to know that the VNA is a reliable one otherwise you will be making dipoles that are way off resonance. That puts your other gear at risk.
Maybe use it now to build a dipole then connect it to an in line swr meter that you know is reliable. I'm just not sure if I would be trusting that VNA tbh.👍
Nice one fred ... I finally got a real one 13 quid with both rubber washers
Best way to go. Safest.
@@CB-RADIO-UK nice one for the heads up I will put the rubber ducky back on the other one... do you recommend me getting one of these fake nano.. it's in my watch list👍🏽
www.ebay.co.uk/itm/201800104377.... have a look
Seen a mod ... rat tail ground plane...
Quick question Fred....
First ssb.... I've seen your videos championing Ss 6900 n
What about the Alinco Dr 135 dx ( 10dx )
The Alinco 135 is thought to be a step up from the 6900N quality wise although the performance is the same.
Yeah, I know this might seem a daft reason, but I think im gonna go for it, purely for its looks. Not sure if clarifier is "clicky" but the one plus I suppose is the programming cable has an external port.
hay Fred what is the impedance of the antenna, some handhelds use 75 ohms and not the standard 50 ohms
Does not say on the antenna.
@@CB-RADIO-UK you would need to check the impedance with the vna hope it helps
@@fixitdaz Yes i should be able to do that. Thanks
Try get some 12 gauge bare copper wire cut same size as na771 see if swr is diffrent compare homemade one and na771.
Have you tried measuring the SWR on the antennas supplied with the radios.....
Hi yes did that on the first nano video if you take a look.
have try take it outside maybe swr would be lower it could be rf noise in your home or your shed.
Good morning Fred. Could you please try to use analogue SWR meter as a cross reference when testing the fake RH771 at f=446Mhz? TX at max 5W and see the reflected power. Very good video review of yours. Cheers!.
Hi. Sorry wont be able to do that as i dont have the adapters.
@@CB-RADIO-UK Aye, okay and thanks for sharing. Regards. Azlan
I tryed my fake 771. It worked ok at 2m (1,3:1). At 70cm it was a disaster (6:1). I only use it on 2m.
That does seem like a surprising result. Could you perhaps consider sacrificing an 888 by doing a practical test with one of these antennas? A simple "does it actually get fried" / range check should surely be able to confirm whether or not the SWR really is that bad 🤔
Already did that 2 yrs ago :-) Here's the link. ua-cam.com/video/phglrc_af-4/v-deo.html
@@CB-RADIO-UK Thanks! I just watched that video, actually the fake 771 sounded a lot better than the standard antenna.
So, something doesn't add up... This is intriguing, needs more investigation surely? Thanks for the interesting videos.
superb clip bro you should have more views
Special person, your measuring half the antenna system on a handy doing it like that.
Well, rip. Wonder how practical would it be to homebrew handheld antennas because it doesn't make much sense to pay 20 bucks for an antenna for 10bucks bf-888s
Yes thats the prob with cheap radios.
I bought one today this would help me out for cb ham hf also weather noaa sat stuff apt.
great video!!! thanks for upload! .... Try again with 4 radials ground plane of 50cm . Handheld transceiver uses the operator body like Ground plane.
Thanks for the tip!
Have you a way to see if the antenna uses the radio as a counterpoise?I would try a field strength meter and compare the fake to an genuine.2CM3284/KE5SRB.CHEERS from the States mate!
Yes the ground plane angle is interesting.
I bought one that claimed to be genuine (and was priced like genuine) but it scored a 7+ in UHF. But now I know.
Be interested to see how the stock antenna tested to compare
ua-cam.com/video/M1BQJI7K69A/v-deo.html
It is amazing how far off an antenna can be made on purpose. They must think that most radio operators would rather cheap god looking antennas rather than a performer.
Its looking that way Andy. Ive got some further tests to do to find out for sure.
Hi again Fred. Have you considered using a counterpoise or as it's sometime called "a Rat Tail". There are a few youtube Vids about these . With the supplied antennas you only really have one part of a half wave. If you add a counterpoise you are effectively completing the antenna. My friend has tried this on a handheld and got really excellent results. SWR came right down to a useable level and the signal went up by 3 S points. He told me the the counterpoise was 19.3 inches. Just an idea you might consider trying. Cheers & 73s Keith
Thanks for the suggestion. There was a real lift in 446 coms throughout lockdown. Nothing in my area yet but iam hopeful.
I wish to god you would have tried the stock factory antenna on the same set up! that is something i would have definitely done for a video!
I did in the prev video on the Nano
@@CB-RADIO-UK whats it called??
Somebody pulled a boot up on one of those fake nagoyas, and there was no coil, which explains a lot.
Get a linear that uses vacuum tubes instead of solid state components, what about making a Slim-Jim antenna for 446MHZ.
What you are finding out is something I've seen for a long time , basically I ripped apart a cheap 'clone' and it had no loading , the closest it came to resonance was about 160Mhz. The best thing for these is trim them down to a UHF quarter wave!!! I jest you not. The main problem is that people buy these and convince themselves they're an improvement. they aren't. best antenna i've seen is the stock uv5R antenna for tune. great on 2m and 70cm! I guess 90% of the chinese antennas are crap , I have a big pile of them and theyre all shite! please people wake up and listen to this guy!!! I do have 1*771 which actually tunes on UHF and VHF. I also find 701's useless too!!!
John your prob right. When ive finished playing with it i will take these fakes apart on another video and give you a shout out. It will be interesting to see if there is any base loading.
Try it on your antron 99 antenna.
Yes going to try that. Waiting for a adapter connection cable.
Im waiting for delivery of the vna, got the adapter’s, looking forward to your next vid, keep em coming fred.
Don't these antenna actually need a ground plane to function properly?
please your resume of this video about NA 771
Try this one. ua-cam.com/video/phglrc_af-4/v-deo.html
These seem to be really bad fakes! I saw some other videos testing the (fake) NA 771 with much better results! There is also a video were they open up both a genuine and a fake antenna. The genuine had some matching circuitry in the bottom part with small coils and little caps! So i guess they do a quick manual matching for each antenna - resulting in the higher price tag. With my (probably fake NA 771 but for around 6 Eur) i managed to hear the ISS space station 3 times when it passed. I wasn't able with the orig. baofeng antenna (signal stick copy). Also try to use a counterpoise (wire attached for virtual ground) - this can really change a lot! Consider in real life your hand and body would act as a counterpoise for the antenna!
Yes i did crack one of these open on another video.
Great video! I always stick with Diamond and Comet, you get what you pay for. The videos answered a lot of questions. WA2TWF
Yes its sometimes worth paying the extra.
What was it like on 70cms?
Not tried 70 cm yet.
It's more likely that the connectors get destroyed with the wrench.
Looks like your antenna mount ground plane is to small.
What about VHF 138-174?
Did not test down that far on this video.
Go for it, I'd like to see! I've got one of these fake 771s and it does work better on the ham bands than the stock antenna, more on 2m than on 70cm (maybe not surprising because of the physical length).
I tried ordering a Nano VNA but the seller asked me to cancel for some reason. Not got round to ordering another one.
Use Diamond antennas on Yaesu HT's.
It's never gonna measure right without a ground plane on the aerial to balance it out.
Unless you are measuring a Slim Jim you must have a ground plane 😉
Any aerial without a decent ground will peg the meter as you found out with your loft aerial experiments 😊
Yes thats making sense. I will be trying the antenna attached to the meter on a future video to see if that balances out.
Use those antennas for receiving only!! \scanning!!!
50 Ohm or 75 Ohm kabel ?
Patch lead is 50 ohms.
Not convinced this test is accurate as the antenna has no ground plane, mounted on a car or handheld held in hand the result would be different. The mag mount alone is not enough. It has to be connected directly to ground through body or car, if not the ground plane/radials need tuning. I would check on car for best result, if only using on PMR you can cut the antenna to a quarter wave whip, the antenna is a 1/4 wave whip for 70cm with a trap/loading coil added. On 70cm the antenna only transmits from about 17.5cm of the antenna. On 2m it works as a top loaded antenna. 2e0deq.
Coincidentally, I was testing my NA-771's this afternoon before I saw your video, having also acquired a NanoVNA. I tested how others have suggested - attaching the antenna directly to the VNA (with a gender converter where necessary) and holding it like I would a radio.
I'd (wrongly) assumed that Nagoya was a cheap (mainland) Chinese brand, and hadn't realised it was actually in Taiwan and rather better, hence worth faking.
All three of my NA-771's were fake, but at least usable, and with roughly the same curve. Optimum SWR around 200MHz but usable (just - SWR
Interesting results. Just goes to show that not all fake 771's are bad and most are prob usable. Just no real quality control.
@@CB-RADIO-UK On second thoughts, only just about usable. ;-)
One of them I only ever used on 70cms (a slightly unusual yellow one that I bought to match my slightly unusual yellow BF-888S) so I decided to cut it down. As predicted, it's a simple steel (?) cable, quarter wave resonant at around 200MHz. Why does it seem thicker towards the base? Simply 'cos there's a double thickness of shrinkfit. Anyway, I chopped it down with a bolt cutter, carefully removed and transferred the rubber titty off the end, and it works a treat. SWR better than 1.5:1 over both 70cms and PMR446. ☺
I'll carry on using the bogus Diamond - it's obviously fake, but it works fine - and keep the "Nagoyas" for emergencies only. Though I might treat myself to a genuine one from a UK source - my TYT handheld is opposite gender to my Baofengs and using a coupler is a bit fiddly.
I'll add that I checked the various stubby antennas that were supplied with the radios, and they were all fine. The optimum SWR tended to be a little lower - about 410 - 420MHz - but still well below 2:1 on 70cms / 446.
Nagola?
It’s crazy what’s the différence building à fake one and true one ? We are not talking about Rolex watch!
It’s ruber and copper wire...
VA2WF
The next 771 video i will open up the fake and look inside
😍Love you Fred😍
Hey HI GUYS ! Where you been bud ?
warning!
DH-771 antenna is fake
this antenna only works for 1.1Ghz-1.7Ghz
Ere, aint you got lovely skin
LOL
why dangerously?
Hi SWR could blow your radio.
Es para VHF y UHF...... No solo UHF
Retevis 771 is much better than Nagoya 771 (no fake)
8:37
I just find the pronunciation of nagoya with an L interesting
Plandemic 🐑
Good info Fred,
56CT004
GLENN
Erroneous NOT a test. Just a waste of time.
you talk a lot
Then mute the vol.