Is it SWR Safe ? Fake Diamond Rh-770 2m/70cm Telescopic antenna.
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- Опубликовано: 16 июл 2020
- Is the SWR safe on these very cheap Rh-770 2m/70cm Telescopic antennas from Ebay / Amazon. Tested with a Nano VNA meter.
Fake cheap NA-771 FM test here. • Fake Nagoya NA-771 FM ... 
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I just got this antenna. It works extremely well on the MURS band (154 MHz). 1.02 SWR. On FRS (467 MHz) with the antenna collapsed the match is 1.03 SWR. Perfect!
It should be suitable for GMRS as well then. Thank you I was just looking to see if I should buy one.
It slightly outperformed my nagoya-771 so I guess it’ll do. Can’t wait for my 48.8inch abbree to arrive next week
It's nice to know that some knockoff's can actually perform Fred.
Hi Andy. Yes this one works pretty good. Ive never tested it before but had already worked out its best config with trial and error. nice to hear from you bud.
I got a chineese battery charger it blew up
I just got one on eBay and tried it with my nano vna. Great SWR on VHF but very very poor on UHF. I can fiddle w or h the length and get it down but still over >2.
I got this antenna to use on a tripod without ground plane as I thought it was a 1/2 wave (at least on VHF) and 5/8 over 5/8 on UHF, also not needing a ground plane.
I assume this really can’t be used fully extended on both bands and will need ‘fiddling’. Unless the knockoff I got is just a bad one.
Any good places to order ones that might work better?
I haven’t found any dual band antenna that would mount on a tripod without counterpoise and is small enough pack in a suitcase except this one…
Fred,
I always use the 446 Mhz frequency.
If I understood correctly, for this frequency the best option is the top section full opened and the bottom section opened only 1,5 cms ?
Thanks a lot for your answer.
Hi David. TBH iam not sure.
@@CB-RADIO-UK
On your video you have tested at 445 Mhz, no ?
And I believe that you talks about to have the top section full opened and the bottom section opened 1,5 cms, is it correct ?
i cannot figure out what lenghts to extend for 2m and 70cm. nano vna didn't help. Wasn't the antenna supposed to be extended half for 70cm and fully extended for 2m? it would make sense. only a few has nanovna and just 10 years ago a vector analyzer costed 4/8000$ and this antenna has been around for more than 10 years
Nice antenna for your handheld scanner radio
Nice review Fred. It seems like this
knock off dual band antenna for the
price performs well being able to adjust
it. The Nano VNA is a good way to
graphically show the high and low
points of antennas. This antenna certainly performs better than some of
the knock off Nagoya ones you
previously showed results to us.
I wonder for use in the US, where 222-
225 Mhz is available, what the SWR
looks like, maybe with adjustments?
It should tune to those freqs. In theory its total wide band
Have you thought about going for your foundation license?
Could be an opportunity for fred in the shed 3 :)
Hi. Dave. Yes i prob will one day when i have a little more free time. Iam really enjoying 11m SSB at the moment. Thanks
Hi Fred greetings from Brighton
Greetings.
Thay really good to listen to ham radio satellites with and the iss
They really improve gain on receive.
@@CB-RADIO-UK you should have a try at the satellites and have a listen to them I'm m6 so I use them it's pretty easy to do as long as u have the right frequency and a sat tracker app I could help u if u were interested pall
Satellites are a hoax and the iss.
www.whale.to/b/satellites_q.html
@@paulhotson5820 I don't usually engage with Flat Earthers but you can literally prove the existence of radio amateur satellites (including the ISS) by observing the doppler shift on the frequencies they transmit when they pass overhead. Just like the siren of an ambulance or police car appears to change when it passes you and gets further away, you'll be able to observe the same with a cheap handheld radio. As the satellite passes (and gets further away) the frequency shifts and you need to adjust the radio accordingly to compensate. With some simple maths you can predict where the satellite is, plus you can calculate the offset and adjustments you need to make at a given time. This of course changes where you are in the world at that particular time, so my offset in one part of the world will be different to yours. You can try this tonight, the ISS broadcasts APRS packets, get a cheap Baofeng radio and tune it to 145.825 MHz FM, predict the pass of the ISS (using a website or smartphone app) and listen, you'll hear the packets, the next time there there is a clear pass you can adjust the offset up or down and hear it for slightly longer. You can also decode the APRS packets with various free software applications. If you want me to help you with getting this hooked up and how to do it, let me know and I'd be happy to help.
This is exactly why i ordered one. I use a nagoya 771 and i can get the iss alright but satellites only a blip here and there. I ordered this antenna and an abbree 48inch folding antenna. Fingers crossed I can make some contacts on cube sats soon
👌
Fred any local rig doctors around
There are a few still left but it depends on your area. Funny but thinking today of making a fred2 chat video of early rig doctors
I can't find one locally i am in just off junction 26 of the M25 Waltham Abbey. Do you know one any where in a 50 mile radius wil do?
Well i see the point of these antennas but because my little brother will play with it im propabaly gonna go with a tactical one because they are designed to be folded unlöike telescopic ones
Don't bother with those tape antenna. The swr is horrible. A Nagoya 771 will get you as many or more far's out of your radio. You can gently rubber band or Velcro band the antenna, you can also run an extension cable and have it run to a backpack or back of a plate carrier.
May not look as tacticool but you will get better far's.
I own 3 different brands of tactical folders all of them perform poorly compared to a 771. I can hit a 20 watt repeater (it's on the 75th floor of a highrise) 30 miles away with a Baofeng and a 771. I cannot hit that repeater with any of the folders.
He thanks for the input after Reading your comment I think that what I'll do is get a pretty good rubber duck that can handle a bit of power and attach a bit of string on the end using Heatshrink so I can pull it up using an extension as my main concern was the height as i have experienced that is my main limiting Factor
The center coil is fake there is no coil in it the antenna would be bottom loaded centre loaded or top loaded fake item.
Yup. It’s fake.
Anyone actually opened one to confirm this claim?
I have one of these and the whip desensitises the antenna, it works better without it on.
My neighbour got a (Fake) Diamond 805 S after recieved he installed on the unit. no reception installed on SWR/ impedance check: came out to infinity ohms and 7 to 1 S.W.R.s. He took apart and the 50 ohms disk risistor was not there! 8 and 1/4 turn on .6mm OD? The center stinger reciever is to short by 3/23 and the dialectic is garbage! FAKE! FAKE!! FAKE!!! P.O.S.
First!!🍺
First well done :-)
@@CB-RADIO-UK just off next door to Fred 2 to watch the other one!😁