active antenna

Useful information regarding antennas for SDR products.
barrykiss
Posts: 8
Joined: Mon Mar 05, 2018 3:56 pm

active antenna

Postby barrykiss » Mon Mar 05, 2018 4:51 pm

hi all just got ersp1 had rsp 1 for several years!
I have a discone on pot a
skyscan on port b
now setting up the hi z for for lf.
i have a 1:9 balun i am now getting an activeantenna -£20-40.must have a dc supply?mains adapter.
can anyone reccomend an antenna on ebay a suitable antenna please/
i cannot solder now as lost rigt arm -stroke!! callsign g3mtd
i can add a random long wire outside.
email barrie@kissack.org.uk
based in north deven uk
Last edited by barrykiss on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

Paul
Posts: 229
Joined: Fri Feb 17, 2017 9:52 am

Re: active antenna

Postby Paul » Mon Mar 05, 2018 5:34 pm

Hi Barrie
I am hesitant to make recommendations based on my shallow experience.
However, I have one of these -
https://www.ebay.co.uk/itm/MiniWhip-Act ... Swc-tY63MT
It works very well (well grounded) atop an 8M carbon-fiber pole (non - conductive mast important I believe).
This antenna is far better than a simiar product that I previously tried.
I find that this works very well from VLF through the 4Mhz range and reasonably above this (improving with increasing frequency).
I have connected it to Port A and Port B without noticeable difference (currently on Port A)
I have a long/random-wire connected to the Hi-Z Port via a 9:1 balun (works well).
I also have a H/V/UHF Discone (Currently on Port B)
Magnetic loop antennas (particularly Wellbrook) are highly recommended by very experienced operators (you may see threads on here concerning these).
I wish you well and hope you enjoy the new device.

Reason: No reason

barrykiss
Posts: 8
Joined: Mon Mar 05, 2018 3:56 pm

Re: active antenna thanks!

Postby barrykiss » Tue Mar 06, 2018 11:32 am

hi paul that is exactly what I want-ordered!
there are so many on ebay I was looking for one a a few others have tried.
this one has good reviews!

what length of antenna have you use?
i could put up a 70ft long wire if iwas stillable to climb a ladder!
thanks for reply
regards
barrie
Last edited by barrykiss on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

Paul
Posts: 229
Joined: Fri Feb 17, 2017 9:52 am

Re: active antenna

Postby Paul » Tue Mar 06, 2018 7:12 pm

Hi Barry/Barrie
This is the long-wire antenna that I have feeding into my HI-Z Port:
https://www.ebay.co.uk/itm/SHF-80-The-W ... SwPgxVTQxD
I am well satisfied with it (RX only - I am neither licensed to transmit on Ham radio nor do I have equipment to dos so.).
I think that this may be a good option for you as although I have mine conventionally hunng (but only about 6M up), you will note that it is claimed to work well when less facourably strung around.
The only negative comment that I have to make is that the little plastic "nut" on the balun's wire attachment is easily damaged (thread stripped) and I had to substitute - not a big deal and it looks, from the accompanying photograph on the advertisement that it may hace been replaced.
Comment: Perhaps, before you hang out a long-wire, it might be worthwhile trying your ordered mini-whip on the HI-Z Port, whilst although I never have, others seem to have done this and achieved good results.
I have not done so because the MW/FM filter on Ports A & B work svery effectively and in my case at least and the mini-whip on eiither Port A or B outperforms the long-wire at the lower frequencies in any case - but of course everyone's setup is going to differ for one reason or anoter.
I do hope you achieve satisfying results and good luck.

Reason: No reason

barrykiss
Posts: 8
Joined: Mon Mar 05, 2018 3:56 pm

Re: active antenna

Postby barrykiss » Wed Mar 07, 2018 3:38 pm

thanks for reply.
I will try that first.
try climbing a ladder with only one arm!!
regards
barrie
Last edited by barrykiss on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

Paul
Posts: 229
Joined: Fri Feb 17, 2017 9:52 am

Re: active antenna - a little info

Postby Paul » Sat Mar 10, 2018 2:04 pm

Hi Barrie
Not going to nag on about this, but I just thought that it might be helpful, if I passed on a couple of things that I found out whilst messing around with these active mini-whips.
1. No good indoors (as the instructions say, if I remember correctly.
2. I would avoid any metal fixings around them (I went to some trouble to provide the first one with a base plate/ground plane - bad idea).
3. The best solution that I have found (and use) is siiting on non-conductive mast/pole - mine is tie-wrapped to it, but duct-tape works too (but may not last all that long).
The advantage of a pole to you, I would think, is that you could fit it at ground level, then raise it (somehow) and my mast is "simply" lashed to a fence, using tie-wraps again, but of course anything suitable could be used.
4. They really do need the coax to be well grounded to get the best results from them.
I hope that you manage OK.
Best Wishes
Paul

Reason: No reason

lenahh
Posts: 10
Joined: Sat Nov 04, 2017 8:49 pm

Re: active antenna

Postby lenahh » Sun Mar 11, 2018 8:56 pm

A 9:1 balun, or to be exact a unun is useless at the hi-z port.
Your wire will have almost any impedance depending length to frequency relation.
What impedance do yo expect at a 21m wire in the 80m band? Right, very low. Transformed 9:1 results in much to low.
What you need is a matching unit build of to variable capacitors and a switchable coil.
I'm using a Thieking & Koch DE-32, witch works quite fine and gives you a nice preselection.

Reason: No reason

Paul
Posts: 229
Joined: Fri Feb 17, 2017 9:52 am

Re: active antenna

Postby Paul » Mon Mar 12, 2018 7:15 am

[quote="lenahh"]A 9:1 balun, or to be exact a unun is useless at the hi-z port.
Hi there
With due respect to someone with no doubt far more technical kowledge than myself, I have used this antenna (see link):
https://www.ebay.co.uk/itm/SHF-80-The-W ... SwPgxVTQxD
both with and without a 9:1 balun on he HI-Z Port of my RSP2 and the inclusion of the balun results in considerably improved (quieter) reception.
The other thing that I am guilty of, is having the balun and feeder on my inside windowsill, the only locally generated that originated in my location appears to be computer generated (located about 30cm from the balun and very close to the feeder).
I regularly, clearly receive a volmet station located more than 9800km from my location at various times of the day and overall performance is quite satisfactory as far as I am aware.
So, might it not be worthwhile to try either option?

Reason: No reason

Strykar
Posts: 6
Joined: Thu Apr 27, 2017 4:04 am

Re: active antenna

Postby Strykar » Tue Mar 13, 2018 2:37 am

Paul wrote:Hi Barrie
However, I have one of these -
https://www.ebay.co.uk/itm/MiniWhip-Act ... Swc-tY63MT
It works very well (well grounded) atop an 8M carbon-fiber pole (non - conductive mast important I believe).


Paul, I bought the exact same antenna hoping to use it with the High-Z port after reading other suggestions on here.
Your tips here have been great, I was going to use a metal mast. Perhaps I should create a new post for this?

I have a few more Qs about this very mini-whip:

    1. How have you grounded the coax, got a photo?
    2. From the SDRPlay docs I read about joining N and GND on the High-Z port to the coax, is this what you have done? I have connected the coax's center wire to P and the outer braid to N, I am unsure how to ground it.
    3. I'm going to order a 1:9 HF balun and try myself after reading your post.

Thanks,
Avi

Reason: No reason

Paul
Posts: 229
Joined: Fri Feb 17, 2017 9:52 am

Re: active antenna

Postby Paul » Tue Mar 13, 2018 7:03 am

Hi Avi
I'm certainly not setting myself up as any kind of expert, merely passing on my experiences where they may be of assistance to others "just starting out."
Please note that i am using the HI-Z port myself with a long-wire antenna and 9:1 balun and not the mini-whip, which is currently on Port A to take advantage of the inbuilt mf/fm filter (wihout a balun).
SDRplay recommend using the HI-Z port for all HF/LF/VLF (and they know what they're doing), I am getting what for me are "satisfactory results" down to tens of khz with the mini-whip as fitted.
However, others have reportedly used the HI-Z port succssfully with the mini-whip (I have no idea how it may compare - I have not tried it).
This link should take you to the illustration that I used for guidance in connecting to the HI-Z port:
https://www.sdrplay.com/wp-content/uplo ... uidev2.pdf
Grounding of the mini-whip on the mast is via as heavy (as I found practicable) earth-wire connected to one of the screws on the bottom of the antenna housing, which attach the bnc mounting, using a terminal connector and a proper, approxiately 1M long earth-spike.
I am unable to provide a useful photograph, because it's all covered up with waterproofing (I hope) self-amalgamating tape.
NB: The best reception that I get with this antenna arrangement is from VLF through to <5Mhz and (usually) >8Mhz (in which ranges it is a toss-up between it and the long-wire).
It has been a very good buy as far as I am concerned - I hope that it wil work just as well for you.

Reason: No reason


Return to “SDR Antennas”

Who is online

Users browsing this forum: No registered users and 4 guests