Advice for soon purchase

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corbintechboy

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Getting to be tax time again. This means research has started and time for me to think about my next purchase.

I am trying to decide what is right for me. I have the Eton E1XM and the radio is great. The only real problem I have with the Eton is the noise is a bit high here. I can move the radio around and find spots that are not so noisy.

Here's the deal. I live in a mobile home at the moment (hope to buy a house soon). I have a back porch and have a wire going into a 9:1 balun. The wire is about 50ft long and I have it in a loop like shape under the eave of my back porch. Works great, the problem is the inherit problems with a long wire and the noise that is included. Pulls in good signals as well as the noise.

What I want to do is get a SDR that is not prone to noise. I had an R 8 and that radio was near silent here with the same setup. I would like to get a radio and a antenna (purchase one). I would like to know what you guys might recommend.

I will have 1500$ at the top of my budget and would prefer to spend less if possible. I would like that to include the radio and an antenna solution. I cannot have an outdoor antenna and I get away with what I have because the current wire actually fits between the door and the jam and I didn't have to add any holes. The new antenna could be placed right next to my desk here and be in a big sliding glass door facing south.

Any advice is greatly appreciated.
 

corbintechboy

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Really no one?

I was hoping Token would jump in since he has a large collection of SDR radios. Or anyone?

I would just really just like to know which radio is least prone to be noisy. I can figure out the antenna.
 

majoco

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There are two sources of noise. One is in the early stages of your receiver, the other comes down the antenna wire with your signal.

To check if the noise is being generated within your radio, run it on batteries, connect the external antenna, tune to a weak station, disconnect the antenna. Now listen to the noise from the radio then without adjusting anything on the radio, reconnect the antenna. If the apparent noise increases significantly, then there's not a lot wrong with the radio. Now run the radio on it's mains power supply - does the noise increase? If so, there's one problem solved.

Now to reduce the noise coming down your antenna - is it being generated from within your mobile home? TV's, switch-mode power supplies, CFL bulbs, set-top satellite boxes are all favourite noise generators. Same test - radio on batteries tuned to a weak station - go round the house turning things off at the wall socket - you may find one or two things that are producing most of the noise.

Next thing - get your antenna up and high - coiled around the front porch isn't going to get much signal.

Let us know what you find.
 

corbintechboy

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Let us know what you find.
Thanks for the reply.

I have done these things. Here is what I found:

On batteries it is close to silent when away from my PC (about 1 S unit of noise).
With AC connected with whip down and no external antenna hooked up, I get about 1.5 S units of noise.
Antenna extended and plugged in away from PC, I get about 3.5 S units of noise.
By PC with external antenna connected I get 5-7 S units of noise.

I had a drake R-8 with the same antenna hooked up and the noise floor was very good IMHO for a long wire, about 1.5 S units of noise.

This tells me that some radios are more prone to noise then others. I have also plugged the Eton in and turned off all breakers in the house except the one used with no change. I am certain a better antenna will more then likely take care of some of it, but if it is indeed prone to noise the radio may not become truly enjoyable until I get a proper antenna.

The antenna I am using has logged stations from around the world. I have really dug out some nice DX with the setup I have now. From where I sit here perched on a hilltop, the antenna in theory is up pretty high.

So my PC might be a bit noisy. I built my machine and there are no cheap components inside. So I would call that the nature of the beast. I would like to get into SDR to heighten the experience. If noise however is going to be a huge issue because of my PC, I don't know what to do. I have a slew of chokes installed all over the place. I would also think my lack of a ground might be causing some issues, in my defense there is no logical way for me to do that.

With all things being what they are, would an SDR be prone to the same thing to a higher degree being married to a PC? Or could I find the same thing I found with the R-8? I hated I had to get rid of the R-8. But it sat on my table because it was to big for the desk and my son spilled milk very close to it. So I decided the demise of a fine radio like the Drake was not going to be because someone spilled some milk. I would have indeed cried over spilled milk if it would have got the Drake. The Eton however fits nicely on my desk so no worries.
 

E-Man

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I would start at the antenna, explore your options, perhaps you can be creative with a outdoor antenna. If you have already done that, and your current antenna is the best you can do in your environment. Then maybe DSP with your E1 would help? something like the CLRspkr:

West Mountain Radio - DSP / Speakers
 

corbintechboy

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Thanks for the replies.

I started to try an investigate the noise. I found some interesting things:

At 4300KHz there is a sound like electrical? It is not consistent. It's like a very powerful static and it repeats ever 200 or so KHZ. At around 6500KHZ my noise floor drops to 1 S unit (which is great). As I move up in frequency more noise is introduced to the point of 9 S units and even plus. The noise starts repeating again.

I don't think this noise is anything generated in the house. Our power lines are buried and it has me thinking about this box I have outside. It is a mesh of cable and phone inside a box for the whole neighborhood. I am going to test this further.
 

majoco

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I don't know anything about the E1, but just have to ask this - is there a proper external antenna connector that disconnects the whip, or are you just connecting your longwire to the whip antenna?

To quote from RadIntel:

If you wish to use a high impedance antenna, such as a random wire, you can either clip it to the whip or use a balun to convert it to low impedance. Either method should work…the low impedance solution has the added benefits of more consistent reception across different frequencies and less local interference if that is an issue in your area.
 
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corbintechboy

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I don't know anything about the E1, but just have to ask this - is there a proper external antenna connector that disconnects the whip, or are you just connecting your longwire to the whip antenna?

To quote from RadIntel:

If you wish to use a high impedance antenna, such as a random wire, you can either clip it to the whip or use a balun to convert it to low impedance. Either method should work…the low impedance solution has the added benefits of more consistent reception across different frequencies and less local interference if that is an issue in your area.
I am using a 9:1 balun. The radio has a switch for external/internal antenna. I am using a PAL adapter hooked to my coax.
 

corbintechboy

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An update.

Hooked up my softrock to the same antenna, no noise on 4300 KHz and listening AFRTS out of Florida with no issues. Low noise and would not be able to hear it otherwise.

So this brings me back to my question. Are some radios more prone to noise? And if not is something wrong with my E1? I wouldn't see how it is like brand new and has never been connected to an antenna during a storm or anything. The E1 would never hear AFRTS like this, it would be buried in noise.
 

ka3jjz

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There was something on the E1 Yahoo group a while back about crappy wall warts causing noise issues - it's been too long since I read it. Are you using the OEM wall wart? I doubt the radio is defective (although it's possible), but if I had noise issues like yours, that's certainly one obvious place to start.

Some radios are indeed noisier than others - better shielding around the processor, perhaps around the display itself - these and other factors cost cash, and sometimes manufacturers just don't take the time to do it right.

Keep in mind, too, that's it a rare PC that isn't itself noisy (although there are lots of ways to quiet one down). With all the power in SDR, you're going to hamstring yourself if you haven't quieted your PC down.

best regards...Mike
 
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corbintechboy

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Further testing has reveled that the wii was the cause.

I had no idea my wife turned the wireless on and it was spitting RF all over the place.
 

corbintechboy

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WOW!

I never had any way to ground the outer coax and never tried. There is no way to make a permanent solution and I know this.

I grounded the coax to the frame of my electric box and WOW! My noise floor is about flat lined. I never knew this radio was capable of being this silent.
 

Sol100

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Urban RF Noise

Hi there,
Noise is a big problem in all built up areas. Every appliance these days seems to produce some form of unwanted RF. Touch lamps, dimmers, pool chlorinators, washing machines and plasma TV's are just a few of the items that want to destroy your noise floor. In some places the utilities use the mains as a transmission medium not to mention some new domestic electrical control and computer systems treat the mains as a computer network system.
I my area in Perth Western Australia our soil is such a poor conductor that our electrical authority require that the neutral and earth be joined, usually in the meter box. The earth is then bonded to a water pipe and an earth stake thats driven into the ground nearby.
If I take a portable radio and place it near any plumbing or cable the noise is so great that it destroys even reasonable signals. One cant use the house plumbing or even an earth stake driven in the ground near pipes with out introducing noise.
What I had to do to get a reasonable (not perfect) reception was move the antenna away from the house.
A home made 9:1 toroid balun that has the coax isolated from the earth antenna winding works well. A reasonable length of 50 ohm coax doesn't have much loss on short wave frequencies so the whole lot can be moved away from the house.
I also find in my case that if I keep the coax floating (not earthed) there is less introduced noise.
For those that want to do their own 9:1 antenna matcher I also found the recommended 30 to 10 turns not as good as 15 to 5 for a broad coverage to 30 MHz.

A radio is only as good as it's antenna.
Sol
 
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