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NASA HF ACTIVE ANTENNA
Posted: 30 Jan 2018, 21:53
by gerald123
hi i am thinking of getting the ....nasa hf active antenna .has any one used them and are they any good for the ameture bands and air bands on hf...
Re: NASA HF ACTIVE ANTENNA
Posted: 30 Jan 2018, 22:13
by ch25
Link?
Re: NASA HF ACTIVE ANTENNA
Posted: 30 Jan 2018, 22:26
by gerald123
Re: NASA HF ACTIVE ANTENNA
Posted: 30 Jan 2018, 23:05
by gerald123
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 08:10
by ch25
I was using miniwhip active antenna, performing well. This antenna seem to be similar.
Do not forget, that you gonna need power adaptor.
Chris
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 15:15
by gerald123
ch25 wrote: ↑31 Jan 2018, 08:10
I was using miniwhip active antenna, performing well. This antenna seem to be similar.
Do not forget, that you gonna need power adaptor.
Chris
just orderd this one..a bit cheaper...
http://www.ebay.co.uk/itm/Mini-Whip-HF- ... 1438.l2649
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 15:18
by ch25
Good choice.
Chris
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 15:43
by gerald123
ch25 wrote: ↑31 Jan 2018, 15:18
Good choice.
Chris
thanks for the replies ....will let you know how i get on with it.
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 19:32
by Auldgeek
gerald123 wrote: ↑31 Jan 2018, 15:43
ch25 wrote: ↑31 Jan 2018, 15:18
Good choice.
Chris
thanks for the replies ....will let you know how i get on with it.
I have the very same active aerial and it does work well. My main RX aeral is a Wellbrook ALA1530S+ Imperium loop. It's a superb aerial and I have to say the miniwhip while not as good, is a decent performer. Factor in the price and you have a bit of a bargain.
A few tips for you.
Try and get the aerial as far away from the house as possible to reduce any hash.
Ensure you make the coax connection waterproof as any water ingress will be fatal for the amplifier
Double check that you have breathing holes to prevent moisture from building up
Re: NASA HF ACTIVE ANTENNA
Posted: 31 Jan 2018, 20:34
by ch25
My advice: use ferrite clamp-on cores right under antenna and before coax entrance your house. 10-15 each side. It will help a lot to reduce coax acting as antenna and bringing all the noise to your rx.
Or better 2x choke balun on FT240-43 core winded 2x 9 turns.
http://www.m0pzt.com/choke_balun.png
You can cut 10dB of noise. I recommend to read and apply:
http://active-antenna.eu/tech-docs/comm ... ftp-10.pdf
Use good, double shielded coax, quality CATV 75Ohm is very for for that.
Chris
Re: NASA HF ACTIVE ANTENNA
Posted: 01 Feb 2018, 10:52
by Admiral
I have found with my PA0RDT active antenna that I get better performance and better signal to noise by mounting it on a non-metalic pole. I have mine on a bamboo pole, I am guessing the fishing type poles would be good too.
Re: NASA HF ACTIVE ANTENNA
Posted: 16 Feb 2018, 12:19
by gerald123
ch25 wrote: ↑31 Jan 2018, 08:10
I was using miniwhip active antenna, performing well. This antenna seem to be similar.
Do not forget, that you gonna need power adaptor.
Chris
hi .i have now got the antenna..i have heard that it would be a better idea to use a 12v battery if so what amp should it be ......also would any 12 v power suply should i use...
Re: NASA HF ACTIVE ANTENNA
Posted: 16 Feb 2018, 14:47
by owza
Whatever you do, watch out it doesn't have any reverse voltage protection. I damaged mine whilst it was on the chimney stack!
(edit, If we are still talking about the NASA?)
Re: NASA HF ACTIVE ANTENNA
Posted: 16 Feb 2018, 15:12
by gerald123
owza wrote: ↑16 Feb 2018, 14:47
Whatever you do, watch out it doesn't have any reverse voltage protection. I damaged mine whilst it was on the chimney stack!
(edit, If we are still talking about the NASA?)
i got this one insted..but same aplies.....
http://www.ebay.co.uk/itm/Mini-Whip-HF- ... 2749.l2649
Re: NASA HF ACTIVE ANTENNA
Posted: 16 Feb 2018, 15:15
by gerald123
i am thinking of hanging it outside bedroom window .....to try it i have not got a garden.i know it should be further away from house ...