beginners question...

dc99 · 24-02-2021 10:00pm #1

Hi,
I tried SDR previously (Neoelec NESR SMART and a ham it up). I found it useless - but then again my antenna may not have been very good.
I got a load of white noise and was only able to receive broad cast stations.
I tried attaching the included Balum 1:9, to a long piece of wire (but I'm so inexperienced that I don't even know if there is a proper side to connect the antenna wire to on the Balum - I think it doesn't matter?).
I tried the included antennas (small whip on a small stand) and did not do any better on the reception.

Anyway - I am tempted to purchase the SDRplay RSP1A as i see good reviews. But would like to try it with a "cheap" long wire to start with - to assure myself that I can receive a good bit of the radio bands. (excuse my terminology). (or even re-try the Nooelec gear first)

So with the Balum - what is the minimum length of wire that I should use (I see online that a guy is using 1mm sq wire 15m in length - connected to one side of the balum- but doesn't detail the grounding side of the balum.

Can I attach a similar diameter wire to the other side of the balum and carefully attach it to the earth point on a wall socket (to attached to the house ground/earth) or is this a stupid thing to do (dangerous? - i would not be using any positive or negative conductors to achieve this type of ground - I would use a spare plug - ONLY have the ground wire terminated to the earth pin - with absolutely no other conductors connected to positive or negative in the plug)?

I would be running the antenna wire out through a window temporarily as well. does touching the antenna on a window frame or anything else "destroy" the received signal before it gets tot he SDR unit?

I am looking for a very simple antenna set up (without spending a lot of money) to prove to myself that I can actually receive stuff.
I am interested in receiving amateur band (HF?) aircraft band and possibly VHF amateur bands.

If I can get some decent reception I would look into getting a "proper" antenna.

These may be very basic and dumb questions, but I have no person to ask locally and I'm starting out clueless (I was "into" CB radio a lot of years ago- but forgotten most stuff I knew...)

Thanks in advance

jmcc · 25-02-2021 6:30am

dc99 wrote: »

Hi,
I tried SDR previously (Neoelec NESR SMART and a ham it up). I found it useless - but then again my antenna may not have been very good.
I got a load of white noise and was only able to receive broad cast stations.
I tried attaching the included Balum 1:9, to a long piece of wire (but I'm so inexperienced that I don't even know if there is a proper side to connect the antenna wire to on the Balum - I think it doesn't matter?).
I tried the included antennas (small whip on a small stand) and did not do any better on the reception.

The Ham-it-up does not have any frontend amplifier so it is very dependent on the quality of the antenna. A long wire antenna will outperform the telescopic whip antenna supplied with it. The whip will probably pick up local Ham repeater signals and aircraft band signals.
https://www.irts.ie/cgi/repeater.cgi

Anyway - I am tempted to purchase the SDRplay RSP1A as i see good reviews. But would like to try it with a "cheap" long wire to start with - to assure myself that I can receive a good bit of the radio bands. (excuse my terminology). (or even re-try the Nooelec gear first)

It is a far superior bit of kit and has frontend amplification. The SDRuno software is good too but takes a while to understand. There is also a very active SDRplay group on Facebook. ( https://www.facebook.com/groups/sdrplay/ ) There's also the SDR forum (read-only now) that has a lot of good information. ( https://www.sdrplay.com/community/viewtopic.php?t=4086 )

So with the Balum - what is the minimum length of wire that I should use (I see online that a guy is using 1mm sq wire 15m in length - connected to one side of the balum- but doesn't detail the grounding side of the balum.

A balun converts a balanced signal to an unbalanced signal (wire antenna to coax as an example).

Can I attach a similar diameter wire to the other side of the balum and carefully attach it to the earth point on a wall socket (to attached to the house ground/earth) or is this a stupid thing to do (dangerous?

Results may vary and it could pick up interference from other devices on the same circuit. I've also seen situations where people use radiators (heating) as a makeshift ground. The ideal ground would be a copper rod in the earth. You can buy them from electrical suppliers.

https://rsgb.org/main/get-started-in-amateur-radio/antennas/end-fed-wire-antennas/

You could also use a wire dipole for the bands in which you are interested. It is essentially two bits of wire each a quarter wavelength long.
http://www.arrl.org/hf-wire

I would be running the antenna wire out through a window temporarily as well. does touching the antenna on a window frame or anything else "destroy" the received signal before it gets tot he SDR unit?

If it is insulated, perhaps not unless it is a metal window frame.

I am looking for a very simple antenna set up (without spending a lot of money) to prove to myself that I can actually receive stuff.
I am interested in receiving amateur band (HF?) aircraft band and possibly VHF amateur bands.

The wire dipole is about the simplest and easiest to build as it is two pieces of wire, a terminal block, some coax and a plug (VHF). With aircraft band and VHF, the sizes of possible DIY antennas are smaller and more manageable. One antenna will not cover everything efficiently. With HF, some ropes and insulators might be better but dipoles are very simple to make.

Regards...jmcc

dc99 · 25-02-2021 5:08pm

Hi,
Lot to digest for me. Thanks.

Unless I invest in a good antenna set up the Nooelec is not much good to me? (If reading you correctly). But the SDR Play (1a) will receive a lot more with a lot less antenna?

So your saying i could get interference if I used the house electrical earth system?

Its a PVC window I would be putting antenna wire through.

I know i might not get great reception from my proposed makeshift antenna - but I just want to prove to myself that I am able to get something. Then I can start looking at investing in "proper" Antenna (Bonito Whip?).

Thanks again for the info.

jmcc · 25-02-2021 6:02pm

dc99 wrote: »

Hi,
Lot to digest for me. Thanks.

Unless I invest in a good antenna set up the Nooelec is not much good to me? (If reading you correctly). But the SDR Play (1a) will receive a lot more with a lot less antenna?

The Nooelec is good but the SDRPlay is better. It is has wider coverage and is designed to a higher spec. The antenna is always important but the whip isn't great for much beyond broadcast. It will pull in some VHF stuff like broadcast (relatively strong transmissions compared to HAM or other stuff) and aircraft transmissions due the relative height of the transmitters. A good antenna always helps and one tuned to the relevant bandwidth is always better than a wideband/untuned antenna.

With HF, the signal going into the Ham-It-Up is not amplified before being upconverted (if I remember the circuit diagram correctly). The SDRPlay has a wider coverage and also has a frontend amplifier (controllable from the software).

So your saying i could get interference if I used the house electrical earth system?

It is possible depending on what else is connected to that earth. The main problem with using SDRs isn't generally going to be earthing. It is going to be the RF noise in the HF bands from switchmode power supplies and other things like LED lights.

Its a PVC window I would be putting antenna wire through.

Should be OK.

I know i might not get great reception from my proposed makeshift antenna - but I just want to prove to myself that I am able to get something. Then I can start looking at investing in "proper" Antenna (Bonito Whip?).

Don't underestimate what can be achieved with makeshift antennas such as dipoles. The dipole is about the simplest antenna to play around with. It is just two bits of wire connected to the coax and there's no earth. It is even possible to make an antenna from coax by folding the braid back on the outside of the coax. For HF/Shortwave, the lengths might be a bit long but for VHF, they are quite manageable.

http://www.iw5edi.com/ham-radio/3777/the-vertical-bazooka-antenna

It is possible to pick up weather satellite transmissions with a simple dipole:

https://lna4all.blogspot.com/2017/02/diy-137-mhz-wx-sat-v-dipole-antenna.html

It is possible to pick up aircraft positional data (ADS-B) easily with the Nooelec and whip and plot it with software much like the Flightradar24 site (www.flightradar24.com). That's around 1.090 GHz and the whip can be used for that or it is possible to build a coax collinear which is essentially a few pieces of Coax connected together.

Mad_lad is the chap to talk to about the magnetic loop antennas as he does a lot of experimenting with them.

Nooelec gear tends to be quite good and I've used it. That RF noise generator in the Ham-It-Up is very handy for quick design work. But the SDRPlay is a step above that again. And there is free Spectrum Analyser software available for it and the latest update for the SDRUno software has a scanner option.

Regards...jmcc

dc99 · 25-02-2021 9:58pm

Hi,
Great info.
I think I might have better luck with the SDRPlay initially with a wire antenna.

if I may ask further- connecting one long wire to the Balun I have (the 1:9 that came with all the Nooelec gear i have) one is strung up outside - but the other wire is the one that must go to an earth?

I have attached a photo of the Balun - also have a short cable with a sma (?) connector on each end.

If this is correct - the earth wire from the balun does not need to be the same length as the reception side wire (this must sound dumb - but i don't know ...:-) )

Thanks

jmcc · 25-02-2021 11:40pm

dc99 wrote: »

Hi,
Great info.
I think I might have better luck with the SDRPlay initially with a wire antenna.

if I may ask further- connecting one long wire to the Balun I have (the 1:9 that came with all the Nooelec gear i have) one is strung up outside - but the other wire is the one that must go to an earth?

I haven't used the Nooelec balun and some of the info (from searching) looks contradictory. Some of them talk about cutting links on the PCB which is not a good thing when there is some uncertainty over the outcome.

https://www.amazon.com/NooElec-Balun-One-Nine-Applications/dp/B00R09WHT6

If this is correct - the earth wire from the balun does not need to be the same length as the reception side wire (this must sound dumb - but i don't know ...:-) )

If both wires were the same size, it would be a dipole. The longwire should connect to the rightmost connector in the image, (I think) and the ground wire to the left. There should be a change in signal levels when the longwire (the reception side) is connected.

Regards...jmcc

dc99 · 26-02-2021 11:43am

thanks - loads of info for me again.

Much appreciated :-)

01-03-2021 2:33pm

dc99 wrote: »

Hi,
I tried SDR previously (Neoelec NESR SMART and a ham it up). I found it useless - but then again my antenna may not have been very good.
I got a load of white noise and was only able to receive broad cast stations.
I tried attaching the included Balum 1:9, to a long piece of wire (but I'm so inexperienced that I don't even know if there is a proper side to connect the antenna wire to on the Balum - I think it doesn't matter?).
I tried the included antennas (small whip on a small stand) and did not do any better on the reception.

Anyway - I am tempted to purchase the SDRplay RSP1A as i see good reviews. But would like to try it with a "cheap" long wire to start with - to assure myself that I can receive a good bit of the radio bands. (excuse my terminology). (or even re-try the Nooelec gear first)

So with the Balum - what is the minimum length of wire that I should use (I see online that a guy is using 1mm sq wire 15m in length - connected to one side of the balum- but doesn't detail the grounding side of the balum.

Can I attach a similar diameter wire to the other side of the balum and carefully attach it to the earth point on a wall socket (to attached to the house ground/earth) or is this a stupid thing to do (dangerous? - i would not be using any positive or negative conductors to achieve this type of ground - I would use a spare plug - ONLY have the ground wire terminated to the earth pin - with absolutely no other conductors connected to positive or negative in the plug)?

I would be running the antenna wire out through a window temporarily as well. does touching the antenna on a window frame or anything else "destroy" the received signal before it gets tot he SDR unit?

I am looking for a very simple antenna set up (without spending a lot of money) to prove to myself that I can actually receive stuff.
I am interested in receiving amateur band (HF?) aircraft band and possibly VHF amateur bands.

If I can get some decent reception I would look into getting a "proper" antenna.

These may be very basic and dumb questions, but I have no person to ask locally and I'm starting out clueless (I was "into" CB radio a lot of years ago- but forgotten most stuff I knew...)

Thanks in advance

First of all check out my kiwi SDR here.

http://emeraldsdr.proxy.kiwisdr.com:8073/

This is what you should be picking up with a good antenna and in an electrically quiet country area. Unfortunately I do have some major issues with an Arching ESB 10 Kva line that I have not been able to get the ESB to fix since 2017 but I'm going to send them more evidence today with a polite request to finally fix it before I contact comreg.

The noise on my SDR is intermittent but getting much worse but it should give you a good indication when properly set up what to expect.

Don't forget to switch between USB/LSB for ham radio transmissions.

A dipole and wire antennas are fine for Transmitting but they can pick up noise and long wires can overload SDR's as they don't have very robust front ends so you will have to apply attenuation via the SDR software because overloading can completely wipe out the SDRs ability to hear anything or cause images, this means hearing stations on bands that they're not transmitting on.

The Antenna on my SDR in the link above is the Bonito MegaDipol and while I do not suggest spending so much it is a really great DX antenna, DX meaning good at receiving distant stations, I have a loop on my other SDR which is offline atm after a recent power cut it corrupted the SD card and I have to set it up again anyway, the loop is better at pulling in closer stations or NVIS.

A really superb receiving antenna is the Bonito MA305 FT and while it might seem expensive it is optimised as a receiving antenna with a very low SNR or low signal to noise ratio, in other words it's a very low noise antenna and I highly recommend it. Get H155 coax and the ground spike from Bonito and cut back some of the shield on the coax and ground it to keep static off the coax helping to reduce noise further. The H155 coax is very well shielded.Bonito supply all of this. The antenna can be powered from a 5v USB power brick.

So what I would do first is have a listen around on my sdr and if you are happy enough then invest in the sdr play and Bonito MA-305 FT it really is a great antenna and best of all it's tiny, really tiny but has the performance of a much longer antenna.

Probably your greatest challenge is reducing noise from electronic devices from your own home or if you're in a built up area, apartment, housing estate. Huge causes of noise are imported dirt LED light bulbs, only buy quality brands like Philips and Osram. GU10 LED downlights and smaller are some of the worst offenders and their power supplies.

Laptop, Iphone, Tablet chargers can wipe out entire bands as well as light bulbs so best to do is get a small portable radio, plug them all out when not needed. Solar PV systems can also cause major problems due to their poorly designed and cheaply built inverters.

Some older LCD tv's can also be a tremendous source of noise, plasma tv, the newer LED ones can be fine but some of their power supplies cause weird sounding noises on the SW bands like sirens such as my lg smart tv.

Anyway, tune into my SDR and enjoy, it can be quite busy at times so if there's no slot keep trying, I must get the other one back online. It's a great hobby and I live weeding out really weak DX signals on the commercial SW bands and also listening to DX ham stations.

dc99 · 01-03-2021 6:16pm

Hi

@madLad - Think I tried your Kiwi a couple of times -couldn't connect a few times - but was interesting when I did.

So I have received my SDRplay RSP1a and stuck a 10m length of with into he Balun I have (from the kit I got with Nooelec - I am getting loads of transmissions currently listening to English language transmission from Bejing on 7.255.000 kHz- at around 9dBm (?). (so is this correct to say that it is 7.225 MhZ frequency (SDRuno just seems to give khz)

I may be stupid, but I could find an appropriate earth or ground - but looking on the web it says that for reception I don't really need one? that it is protection against lightening strike? (rear enough in Ireland :-) )

So maybe I'm off on a big adventure with my SDRplay1A as I could receive practically nothing with the nooelec/ham it up etc.

First listen to my new SDR and happy - going to try for come HAM transmission later (I seem to remember I need to wat till evening to get HAM transmissions???)

Thanks all of you for the help starting up.

01-03-2021 7:21pm

dc99 wrote: »

Hi

@madLad - Think I tried your Kiwi a couple of times -couldn't connect a few times - but was interesting when I did.

So I have received my SDRplay RSP1a and stuck a 10m length of with into he Balun I have (from the kit I got with Nooelec - I am getting loads of transmissions currently listening to English language transmission from Bejing on 7.255.000 kHz- at around 9dBm (?). (so is this correct to say that it is 7.225 MhZ frequency (SDRuno just seems to give khz)

I may be stupid, but I could find an appropriate earth or ground - but looking on the web it says that for reception I don't really need one? that it is protection against lightening strike? (rear enough in Ireland :-) )

So maybe I'm off on a big adventure with my SDRplay1A as I could receive practically nothing with the nooelec/ham it up etc.

First listen to my new SDR and happy - going to try for come HAM transmission later (I seem to remember I need to wat till evening to get HAM transmissions???)

Thanks all of you for the help starting up.

Yeah for a long time I had serious issues with Tree 4G and the data was too low so I switched providers and now have no issues except when there's a power cut, I use a big linear power supply to keep the Kiwis free from the noise of switch mode power supplies, this is very important.

A ground is essential because it will eliminate static which can destroy your receiver, forget about lightning, nothing will protect you against a direct strike, in the Summer don't leave your antenna connected when not in use that's rule No.1 because lightning happens in Ireland and it will happen when you least expect it and you will now have a direct way for this to get into your house so when not in use unplug the antenna.

Ham transmissions are 24x7 365 days a week, evening is best below 7 Mhz and above 7 mhz usually in the day but 80m is usually good for local coverage day or night.

Some of the Chinese stations pump out 500 Mw of RF power and that is substantial though some Longwave and Medium wave stations can hit 1 Mw, when you think about that 500 Mw is plenty to cover billions of People if not the whole planet from a single transmitter.

I can't tell you want way to configure your antenna as I don't know what you have apart from some wire, maybe take some pics, post them to imgr then copy the links from imgr and paste them here.

Definitely, if you can at all get the Bonito MA305 FT antenna, it's so small it's unbelievable how well it performs, get a 1 or 2 meter tall galvanized pole and beat it into the ground and attach it to that, ground it there and run the coax into wherever you want.

Most important is keep your antenna as far as possible from the house or any house or sources of noise.

Welcome to the wonderful and addictive world of radio, now go onto the irts website and start studying for your ham radio license, it's a really wonderful life long hobby.

All you need is here https://www.hamradio.ie/course-guide/intro/course_guide.html

You don't need any other material from any other site or app.

beginners question...

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