Fake £3 Nagoya NA-771. Tear down. FM test video here. • Fake Nagoya NA-771 FM ... Radio Hobby great review of a genuine NA-771 is here. myradiohobby.bl...
Clearly, the Chinese omitted the flux capacitor. 😁 Yep, the genuine article has a tuned coil whereas the cheapie had used the equivalent of a bed spring.
You almost got it right. The genuine has tuning capacitors, which are clearly visible at the bottom of the photo, and the inductor is wrapped around an insulator. On the fake, there are no tuning capacitors, and the "inductor" is just a spring.
The coil is replacing the missing length. How you achieve that is a matter of choice. I have many hand held antennas and mobile antenna they are all made slightly differently. They all work well
Fred....the aerial you took apart is just a base loaded whip similar to the springer. But the original has a matching device similar to the Antron. Using the brass shroud and a tapped copper matching device. You certainly get what you pay for.
The cheapo antenna that you opened is doing what it is intended to do. It is making up for a shortened length by using a piece of coiled wire instead of using a stretched out antenna. There is nothing wrong with this design. I hope you can get it back together, it’s fine to use. The true Nagoya is adding superior technology to achieve the same goal.
Ther is nothing superior about adding lossy caps to an shortened aerial that just needs an end fed inductance to substitute the missing length, the stupid thing about the 771 is it should be 16.5 inchs making it a 70cm end fed 5/8th and shortened 2M 1/4wave not the 13 inches it is
Hi Fred nice vid but the fake one I striped had no coil and you could just pulled the plastic shield upwards , turn it in to a 1/4wave whip works better now
The difference is very clear: the real one seems manually adjusted to match characteristic impedance and SWR at the correct frequency. You can see that from soldering 2 small caps on the coil - this seems manual adjustment work and can't be done automatically as each antenna is just slightly different. The fake ones seem all the same, some match better than others but its always luck if they match at the right spot, most won't of course!
have recently bought the small magmount aerial for this, works great in car, and the flat tactical antenna 9 the one that folds in 3 ), great also, folded and unfolded. unfolded it picks upfrom 4 miles away...
I have seen some with the 'coil' as you put it. I think you'll find it's a spring more than loading. I have also seen some that just crimp straight to the end. Thats why in the real world a quarter wave works just as well if not better on UHF
Fred it's nearly impossible to avoid buying these fake antennas, I bought one from a very reputable dealer, put it on the analyser and it was off the scale, the seller replaced it but it was the same. Total junk.....
Yo Fred. Mine didn't even have a coil like that. It was literally just the whip directly connected to the center pole of the SMA connector. Yours must be slightly higher quality than mine was ;) haha
Well, it's much better than I was expecting. The manufacturer didn't just throw a piece of plastic in there. Not saying that it's are good as the real deal; just that it could have been worse. It appears the maker of the antenna was trying to provide a working antenna. Meh. 🔹🌞🌙✨
Test it with a meter (multi meter Fred) to see it the centre goes to the coil/spring or goes direct to the centre whip. I didn't expect to see anything but a soldered connection. It looks as it it is connected to the outer, braid (the spring/coil) but it is hard to tell on this small Laptop screen. Thanks for doing that Fred. Thumbs up!
does not matter which side is connected to the radiator in an antenna, it is an alternating voltage, going from positive to negative , 400,000 times a second.
What I Did Is - I Bought This Antena And Many More And Remade It To A Standart I Need It With Copper Wire And Some Other Parts And Shrinktubes, Vna And Some tests. :) All Of Them Works Like A Dream
Is the coil shorting? it should have a good seal on the wire .. and what colour sleeve did you have when you purchased it ? My gen (hopefully) is a lime green.
I had the same call on 555. Spoke to guy from near Glasgow very clear and on 12 watts on my crt SS9900n on half wave silver rod. I'm down South 3 miles from Gatwick Airport.
I've just realised after watching this that the NA771 I have been using on my uv5r is a copy with blue writing and did only cost couple of quid, I bought them because I thought the stock antenna was pretty naf but what a difference from my home to gainsborough did a 40 mile trip including qsk from Mansfield about 30 miles from me but the terain was pretty much uninterrupted
It looks like a shortened end fed 70cm 5/8th which have a 3 turn coil at the bottom to substitute the missng 3.5in of a 3/4 wave ( or 145MHZ 1/4 wave) which would be 16.5in. an end fed 435MHz 5/8th also matches 145MHz as a shortened 19.5 in 1/4 wave Why make a shortened 13 inch long 430MHz 5/8th? just make it the 16.5in it should be
Hi There Fred , Can you please now cut the rest of that antenna open , Then how about putting it back on your meter & then open up some of the coils to see if the SWR moves .
I Never Understand The Steel Antennas, I Know That The Elasticity Is The Number 1 Thing To Gain From it, But Coil Copper Around It Then Or Copper Coat It. That Will Make It MUCH MUCH Better Antenna
I Assume There Is A Loading Coil becaause Of The Vna's Nowdays, It resonates On 144... But As Long As Distance And Quality - Will Not be Good (No Pun Intended)
That's not a loading coil Fred. It's not tapped for a start. It has no capacitors and it's not insulated from the base and the whip. I suspect that 90% of 771's out there are the same if not worse than the one you have there. Finding a genuine one is harder these days than collecting chickens teeth. de 2E0LFD. 🇬🇧👍😎👍🇬🇧
I bought two of these fake dual-band antennas from AliExpress. When tested with a VNA they and they showed a spike at 205 MHz, and only at 205 MHz. Garbage, don't buy them. Luckily, I got to return them postage paid and got my money back.
Richard Davies: All GENUINE Nagoya antennas have a little inverted triangle inside the first letter "A" of the word "Nagoya"......see link below. imgur.com/UniMR5Z
I got one of these and they are crap. It fell to pieces as I put it on the radio. The connector just popped off with the inner parts. Avoid at all costs.
Depends on pot luck with the SWR. Some are as good as the orig antenna but others feed too much power back to the radio. This one was borderline when i tested it with the Nano meter.
hi fred i've been mucking around with different antennas for weeks around potters bar , best so far seems to be fake abbree tactical 42" (in orange bag) but gives much better transmit / receive than a suppose geniue green bag antenna... keep safe andy
@@CB-RADIO-UK today i received an antena diamond RH 771 for my uv 5r.. made in china with blue stamp the letters and sma -f connector.Maybe its fake..i paid only 5 eyro..Regards from Greece. At least it has good receive,,i didnt try it in TX yet (for distance)
@@CB-RADIO-UK i made a homemade copy of this antena and it workws fine..i can hit repeaters and i have good tx and rx signal...regards,,,73,,,,even i dont have a licence..ps.. i saw yr video and made the copy..
I respect you less for publishing this video. I've just been made dummer. It took you 2.5 minutes to remove 2.5 years of college/university from my brain.
Clearly, the Chinese omitted the flux capacitor. 😁 Yep, the genuine article has a tuned coil whereas the cheapie had used the equivalent of a bed spring.
Is it not a Reverse Flux Capacitor you need or a dual polarity one? You need to charge it up with a bolt of lightning anyway first.
You almost got it right. The genuine has tuning capacitors, which are clearly visible at the bottom of the photo, and the inductor is wrapped around an insulator. On the fake, there are no tuning capacitors, and the "inductor" is just a spring.
The coil is replacing the missing length. How you achieve that is a matter of choice. I have many hand held antennas and mobile antenna they are all made slightly differently. They all work well
Fred....the aerial you took apart is just a base loaded whip similar to the springer. But the original has a matching device similar to the Antron. Using the brass shroud and a tapped copper matching device. You certainly get what you pay for.
Yes spot on Charlie.
I couldn't quite make it out on the small screen I have what was there. But there appears to be no attempt to match anything.
The cheapo antenna that you opened is doing what it is intended to do. It is making up for a shortened length by using a piece of coiled wire instead of using a stretched out antenna. There is nothing wrong with this design. I hope you can get it back together, it’s fine to use. The true Nagoya is adding superior technology to achieve the same goal.
Ther is nothing superior about adding lossy caps to an shortened aerial that just needs an end fed inductance to substitute the missing length, the stupid thing about the 771 is it should be 16.5 inchs making it a 70cm end fed 5/8th and shortened 2M 1/4wave
not the 13 inches it is
@@phillipsmiley5930 The Nagoya 771 is 15.6 inches my guy
@@alienwarex51i3 all the 771 i have are 13 inches long
Hi Fred nice vid but the fake one I striped had no coil and you could just pulled the plastic shield upwards , turn it in to a 1/4wave whip works better now
Oi, you got a liecanse for that thare knife?
The difference is very clear: the real one seems manually adjusted to match characteristic impedance and SWR at the correct frequency. You can see that from soldering 2 small caps on the coil - this seems manual adjustment work and can't be done automatically as each antenna is just slightly different. The fake ones seem all the same, some match better than others but its always luck if they match at the right spot, most won't of course!
That coil didn't appear to be copper. It could have quite high losses due to skin effect.
have recently bought the small magmount aerial for this, works great in car, and the flat tactical antenna 9 the one that folds in 3 ), great also, folded and unfolded. unfolded it picks upfrom 4 miles away...
I have seen some with the 'coil' as you put it. I think you'll find it's a spring more than loading. I have also seen some that just crimp straight to the end. Thats why in the real world a quarter wave works just as well if not better on UHF
Fred it's nearly impossible to avoid buying these fake antennas, I bought one from a very reputable dealer, put it on the analyser and it was off the scale, the seller replaced it but it was the same. Total junk.....
good job Fred from Gary 73.
Maybe check for continuity from the coil to the SMA end. Ground and Hot. 💁🏻♀️
Yo Fred. Mine didn't even have a coil like that. It was literally just the whip directly connected to the center pole of the SMA connector. Yours must be slightly higher quality than mine was ;) haha
LOL slightly i guess. Still poor :-(. Thanks Mark.
Well, it's much better than I was expecting. The manufacturer didn't just throw a piece of plastic in there. Not saying that it's are good as the real deal; just that it could have been worse. It appears the maker of the antenna was trying to provide a working antenna. Meh. 🔹🌞🌙✨
Test it with a meter (multi meter Fred) to see it the centre goes to the coil/spring or goes direct to the centre whip. I didn't expect to see anything but a soldered connection. It looks as it it is connected to the outer, braid (the spring/coil) but it is hard to tell on this small Laptop screen. Thanks for doing that Fred. Thumbs up!
does not matter which side is connected to the radiator in an antenna, it is an alternating voltage, going from positive to negative , 400,000 times a second.
Bob it went straight in the bin weeks ago :-)
@@CB-RADIO-UK Ok, just have to get one.
@@pixotica That is not why I asked though.
What I Did Is - I Bought This Antena And Many More And Remade It To A Standart I Need It With Copper Wire And Some Other Parts And Shrinktubes, Vna And Some tests. :)
All Of Them Works Like A Dream
Is the coil shorting? it should have a good seal on the wire .. and what colour sleeve did you have when you purchased it ? My gen (hopefully) is a lime green.
It was the Orange PVC sleeve.
Should carry a disclaimer Fred that no fingers were cut or hurt in the making of this video 😝
Good to see what lives inside a fake version 👍
The Nagoya is a NOGO...for me !
Thank’s for the démonstration.
Heard a lot of English stations on 11m from up here in Aberdeen today - looking forward to catching you on the air one day!
Fingers crossed. I love E skip.
I had the same call on 555. Spoke to guy from near Glasgow very clear and on 12 watts on my crt SS9900n on half wave silver rod. I'm down South 3 miles from Gatwick Airport.
Very interesting! Thanks for sharing!
1:43 that looks more like a spring to me, but you might call it a reversed engineered loading coil as well...
I've just realised after watching this that the NA771 I have been using on my uv5r is a copy with blue writing and did only cost couple of quid, I bought them because I thought the stock antenna was pretty naf but what a difference from my home to gainsborough did a 40 mile trip including qsk from Mansfield about 30 miles from me but the terain was pretty much uninterrupted
Hi Joe. Its a bit hit or miss but some of these clones work really well.
LOL live and direct... have a good weekend..and stay healthy..
I tuned at around 470 mhz with swr 2
Thanks for that Fred.....best wishes mate.........Bob
Cheers Bob.
Made to work but lacking quality workmanship. Thanks for the video Fred.
Thanks Andy. I see your new radio is coming on nice.
Please everyone just let me state the obvious. Someone has ripped off a million radio enthusiasts including myself, and wish help them do it.
It looks like a shortened end fed 70cm 5/8th which have a 3 turn coil at the bottom to substitute
the missng 3.5in of a 3/4 wave ( or 145MHZ 1/4 wave) which would be 16.5in.
an end fed 435MHz 5/8th also matches 145MHz as a shortened 19.5 in 1/4 wave
Why make a shortened 13 inch long 430MHz 5/8th? just make it the 16.5in it should be
The coil loads for 2m and gives a match for it being a half wave on 70cm
Trouble is no one sells the genuine stuff anymore. Where can i buy a genuine one in the uk?
Best try a radio supplier with its own website and not ebay or amazon. better still once shops open up buy over the counter.
Hi There Fred , Can you please now cut the rest of that antenna open , Then how about putting it back on your meter & then open up some of the coils to see if the SWR moves .
All you need to do is cut a bit off the top and check it is all the way up, it may not even be the full length.
Kev there really is no point. They are poor. ive since got some more in from China which i might cut down.
@@CB-RADIO-UK ok mate , there that bad , I have two some where , I will just put them in the bin now after what you have found .
Yes but does the wire carry on up the antenna ?
It will be just the spring section right to the top.
I Never Understand The Steel Antennas, I Know That The Elasticity Is The Number 1 Thing To Gain From it, But Coil Copper Around It Then Or Copper Coat It. That Will Make It MUCH MUCH Better Antenna
Yes it should be copper all the way. Maybe using sprung or stainless steel prevents corrosion ? Prob just costs. Thanks for youe comments.
I Assume There Is A Loading Coil becaause Of The Vna's Nowdays, It resonates On 144...
But As Long As Distance And Quality - Will Not be Good (No Pun Intended)
if the fake antenna is not broken, it works like the original
True. On the test meter value is aprox same. Small, small diference
I have compared them both in many tests and find them to be the same
Bought one off Amazon, disapointed to find it was a fake.
In my cheap is like the original but without the coil.
I got a fake and a real one... let's see what Fred finds inside!😎👍🏽
Nice video Fred..
Just walk around with a Diamond X50 on your shoulder ....problem solved . Hope to catch you on air soon 305 usb 1RC355
:-)
This is what i am worrying about when it comes to antenna
That's not a loading coil Fred. It's not tapped for a start. It has no capacitors and it's not insulated from the base and the whip.
I suspect that 90% of 771's out there are the same if not worse than the one you have there.
Finding a genuine one is harder these days than collecting chickens teeth.
de 2E0LFD. 🇬🇧👍😎👍🇬🇧
I think they are crap Nagoya 771 anyway I've had a real and a fake one
dh-771 antenna (red) shorten 17 cm for 446 mhz pmr
Heh? You already did the broadcast FM receive test video, I remember watching it.
Yes if you subscribe to fred 2 you often get videos early.
@@CB-RADIO-UK I see, thanks
thx for the vid i now i do not need to do it to my 1
I bought two of these fake dual-band antennas from AliExpress. When tested with a VNA they and they showed a spike at 205 MHz, and only at 205 MHz. Garbage, don't buy them. Luckily, I got to return them postage paid and got my money back.
I got a fake Nagoya 771 like this from Indonesian online shop.
Bad to receive and transmite.
High SWR !!
Good demo. I wouldn’t of know the difference by just looking at them. Cheers
Richard Davies: All GENUINE Nagoya antennas have a little inverted triangle inside the first letter "A" of the word "Nagoya"......see link below.
imgur.com/UniMR5Z
I got one of these and they are crap. It fell to pieces as I put it on the radio. The connector just popped off with the inner parts. Avoid at all costs.
is it bsafe to use?
safe*
Depends on pot luck with the SWR. Some are as good as the orig antenna but others feed too much power back to the radio. This one was borderline when i tested it with the Nano meter.
I agree. Mine antenna Nagoya 771 is more FAKE than yours hahaha. Mine ant dont even have a coil inside.
Did you think you could find Santa Claus inside that antenna?
The question is, how does one tell a fake from the real deal?
Thats the prob
Can someone Field teste this antennas
hi fred i've been mucking around with different antennas for weeks around potters bar , best so far seems to be fake abbree tactical 42" (in orange bag) but gives much better transmit / receive than a suppose geniue green bag antenna...
keep safe andy
Hi Andy. If you get a ssb radio your in an ideal location to join the 305.
First and a like! Greetings from Los Angeles!
Hi to the guy from LA. Greetings from St Albans UK.
Thanks you just saved me $2...hahaha!
warning!
DH-771 antenna is fake
this antenna only works for 1.1Ghz-1.7Ghz
well i guess these fakers see huh these are trendy rgnw lets make em (qulatity level well it works but good? they wont really care)
*The steel spring is a POOR conductor and the signal energy probably never gets to the antenna.*
Fake, fake, fake!
Yes as in the first word on the title.
You ruined a good antenna and you did it in front of hundreds of thousands of people watching 😂😂😂
Don’t worry, they’re still not good ;)
if it works , who cares....
Yeah thats true but you have to watch the SWR. Some examples had an SWR of over 5.0 which can lead to damage.
@@CB-RADIO-UK today i received an antena diamond RH 771 for my uv 5r.. made in china with blue stamp the letters and sma -f connector.Maybe its fake..i paid only 5 eyro..Regards from Greece. At least it has good receive,,i didnt try it in TX yet (for distance)
@@CB-RADIO-UK i made a homemade copy of this antena and it workws fine..i can hit repeaters and i have good tx and rx signal...regards,,,73,,,,even i dont have a licence..ps.. i saw yr video and made the copy..
if it works
..who cares
Retevis 771 is much better than Nagoya 771 (no fake)
I respect you less for publishing this video.
I've just been made dummer.
It took you 2.5 minutes to remove 2.5 years of college/university from my brain.
LOL Says the guy that uploaded "Garbage guy / truck crushes a washing machine" video
@@CB-RADIO-UK Less than an hour...
Is mom's basement getting small?
Your sure putting that college education to good use trolling on the internet. Money very well spent.
@@CB-RADIO-UK "I know you are, but what am I?"
That's what this thread has been reduced to.
Dismissed.
I'll no longer waste my time replying.