Is there a way to cut down the white noise on my reciever, It is overwhelming to listen to it constantly,,Do the higher end recievers suffer from this?,,Any ideas would be helpful(Im using a Alpha end fed antenna that goes out my attic vent window to the fence next to house.
IC-R75 Reception
- Thread starter cmed325
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1. I don't have an R75, but there is probably a knob that controls both squelch and RF gain. Go into the menu and set it for RF Gain.
2. Turn the RF gain up until the noise disappears and then slowly back it down. Adjust it down to where the noise is not so bothersome for you. You may have to turn up the volume a bit after that.
2. Turn the RF gain up until the noise disappears and then slowly back it down. Adjust it down to where the noise is not so bothersome for you. You may have to turn up the volume a bit after that.
majoco
Stirrer
Running any HF receiver with the RF gain up full will bring in a lot of noise - local electrical interference, cosmic noise from distant galaxies (yes!) and even the noise generated with from the receiver itself. This is especially true when trying listen to SSB signals, in the gaps between words the gain swings back up to maximum again. Don't bother with the squelch, it doesn't work very well on HF anyway due to the varying signal levels. Turn the RF gain down until the noise decreases until you can hardly hear it and then just bring it up a little, then adjust the AF gain to a comfortable level. We want the signal to pop out of a quiet background. If you want to test how much noise is coming from outside, just disconnect the antenna and see how much noise remains!
Nice radio - you'll be very pleased with it - just be patient and find out how everything works to get the best out of it!
Nice radio - you'll be very pleased with it - just be patient and find out how everything works to get the best out of it!
ka3jjz
Wiki Admin Emeritus
Don't ignore the power supply - using a cheap one can often introduce noise....Mike
Ubbe
Member
You have to keep interferencies down to make it produce less white noise. Use a coax cable to your antenna and a balun and also decouple the coax by having the coax go a couple of turns in a ferrite ring at the antenna and at the receiver.
Some receivers are better at holding the background noise down, they have a bigger difference between signal and noise.
/Ubbe
Some receivers are better at holding the background noise down, they have a bigger difference between signal and noise.
/Ubbe
ridgescan
Member
What I'm in the habit of doing is I hit ATT, then preamp1 and this will help a lot especially in SSB. For AM SW BCs I will reduce the RFgain just until it matches the signal fade. You'll need more audio gain doing this, which is why I run my R75 through a very powerful A/V unit to 5 speakers. My R75 is in the living room.
I went to the button that says ANT/SET got to the menu where it says RF/SQL,,From there how do i adjust the RF?,,,I lost my manual and could use some help.
Download the R75 PDF manual from the following link. Read page 30 and then page 14.
Instruction Manual
Instruction Manual
Thank you,,Also would a MFJ 1025 Signal Unit help my overall set-up?
I am unsure about the MFJ 1025. I do not own one. Additionally, the noise you have at your location may be due to several or many different things such as noisy power supplies inside your house or that of your neighbor.
An RF choke may also help reduce noise and allow you to hear stations. As you are receiving you don't necessarily need a more expensive one used for transmit. If you get one, dial up some unused frequencies on different bands and note the S level of the noise. Then connect the choke at the antenna and note the numbers again on the same frequencies. Finally, test the choke on the coax near the radio and look at the numbers. You may see the best response with it near the antenna. Some people use chokes at the antenna as well as just before the radio. I use one with my Off Center Fed Dipole antenna and it reduced the noise by 2 dB which is significant. I transmit on that antenna, so I use the MyAntennas common mode choke.
Also, as VK3RX pointed out, who owns an R75, the Icom UT106 DSP module helps with noise they have. I have DSP built-in to some of my radios and use it at times as well.
An RF choke may also help reduce noise and allow you to hear stations. As you are receiving you don't necessarily need a more expensive one used for transmit. If you get one, dial up some unused frequencies on different bands and note the S level of the noise. Then connect the choke at the antenna and note the numbers again on the same frequencies. Finally, test the choke on the coax near the radio and look at the numbers. You may see the best response with it near the antenna. Some people use chokes at the antenna as well as just before the radio. I use one with my Off Center Fed Dipole antenna and it reduced the noise by 2 dB which is significant. I transmit on that antenna, so I use the MyAntennas common mode choke.
Also, as VK3RX pointed out, who owns an R75, the Icom UT106 DSP module helps with noise they have. I have DSP built-in to some of my radios and use it at times as well.
Ubbe
Member
That's a noise canceller. How they work are that you feed your antenna through it and then add a second antenna that must be able to receive the interference with a good signal. The noise canceller then change the phase of one of the antenna signals so that the interfence are in the exact opposite phase to the other antenna and cancel it out.
It needs the interference to come from only one direction, no bounce signals from objects, and there can only be one interfering signal. Any signal that you want to receive that comes from the same direction as the interference will also be attenuated. The manual phase controller has to be tweaked if you change frequency band.
If there's just a general high white noise level then a noise canceller might not work.
The dsp noise reducer in Icom also distort the audio. I think it has 10 levels of reduction and if I go above 2 the audio gets so distorted that I hear voices more clearly without the dsp and with all the noise, compared to the noise reducer set at level 3. The human ear are the best noise filter you can have.
/Ubbe
I'm in an apartment and when I moved here, my HF monitoring was mostly shot. So much noise from probably every possible dirty noise source you can think of was hitting my antennas. Plus, there's a 125KV power sub-station about 100 yards away.
I tried everything including phase type noise cancelers like the MFJ-1025. The 1025 helped some but only on specific sources of noise. Not enough to keep me interested in the HF part of the radio hobby.
I later read a lot about loop antenna's so I finally purchased an original Pixel RF-1B from the original manufacturer.
That thing worked wonders. I finally put the loop on a cheap TV rotor and on the roof of the building with the owners permission. If I encounter noise today, I can rotate the loop and usually still null it out.
Much of the noise hitting me was common mode noise riding in on the coax. The loop antenna de-couples the coax from the loop and its amplifier which is what helped the most I later learned.
I tried various was of de-coupling my long wires I still have out there but with limited success so the loop is still the only antenna I can really use well for HF and below reception.
I can once again enjoy NDB hunting and the loop works great for that!
I do have an R75 but I'd mainly used it for the 6 meter band. I usually use an R9000 or R8600 for 30 MHz and below but since installing that loop, the R75 is now used below 30 MHz as well.
I tried everything including phase type noise cancelers like the MFJ-1025. The 1025 helped some but only on specific sources of noise. Not enough to keep me interested in the HF part of the radio hobby.
I later read a lot about loop antenna's so I finally purchased an original Pixel RF-1B from the original manufacturer.
That thing worked wonders. I finally put the loop on a cheap TV rotor and on the roof of the building with the owners permission. If I encounter noise today, I can rotate the loop and usually still null it out.
Much of the noise hitting me was common mode noise riding in on the coax. The loop antenna de-couples the coax from the loop and its amplifier which is what helped the most I later learned.
I tried various was of de-coupling my long wires I still have out there but with limited success so the loop is still the only antenna I can really use well for HF and below reception.
I can once again enjoy NDB hunting and the loop works great for that!
I do have an R75 but I'd mainly used it for the 6 meter band. I usually use an R9000 or R8600 for 30 MHz and below but since installing that loop, the R75 is now used below 30 MHz as well.
kg4zqz
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i use several methods to reduce 'noise' when using my r75... of course, some noise cannot be fully eleiminated without audio distortion....
1. battery power - this helps isolate any electrical line noise
2. an AOR LA400 loop antenna - expensive, and there are other inexpensive loops - the advantage being to be able to null out noise by loop rotation
3. DSP filtering - a JPS NIR-12 dual DSP unit, which effectively reduces noise
4. UT-106 - not the best, but it can help
5. ICOM filters and filter manipulation
1. battery power - this helps isolate any electrical line noise
2. an AOR LA400 loop antenna - expensive, and there are other inexpensive loops - the advantage being to be able to null out noise by loop rotation
3. DSP filtering - a JPS NIR-12 dual DSP unit, which effectively reduces noise
4. UT-106 - not the best, but it can help
5. ICOM filters and filter manipulation
I know many people idolize the ICOM IC-R75, almost like a cult following! However I've owned two over the years I was very disappointed with the noise and the R75's inability to deal with it, even with the optional over priced/over rated UT106 DSP module. There are ways to make it a little better but you have to know the source of the noise before you can effectively try to eliminate it. The bands/frequencies monitored on the R75 are usually quite noisy to begin with so your efforts might now be very successful when all is said and done.
Looking at your picture I would suggest you start by relocating the loop antenna as far from any electronics as possible and away from the metallic mini blinds. Good luck! I feel your pain.
Looking at your picture I would suggest you start by relocating the loop antenna as far from any electronics as possible and away from the metallic mini blinds. Good luck! I feel your pain.
kg4zqz
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tks! my r75's reception is very good (i can easily listen to 40/80M nets and even DX)... the combination of batteries, loop and the JPS unit eliminate most noise... the r75 is not shielded as well as the AOR receivers (i have 8000s, 8200s, and 8600s), and there is little to no leakage via the JPS (which is built like a tank with thick steel)
i do have to agree about the UT-106... very over-priced... and just about as bad as the DSP in my Kenwood 570D... but OK at the 3/4 levels without too much distortion (the JPS is
my normal S7-9 environment is now quiet on the receivers i use... and if a neighbor decides to use a bad polluter i also have an ANC-4 waiting in the wings
i do have to agree about the UT-106... very over-priced... and just about as bad as the DSP in my Kenwood 570D... but OK at the 3/4 levels without too much distortion (the JPS is
my normal S7-9 environment is now quiet on the receivers i use... and if a neighbor decides to use a bad polluter i also have an ANC-4 waiting in the wings
Ubbe
Member
I had a R75 and a DX394 connected thru a splitter and tried both a loop and a wire and half the times the modified DX394 had the best reception. Even a not so good msi.sdr dongle receiver beats both of them. But they are more than 20 years old and the msi.sdr are just a couple of years in production so are an unfair comparison.
/Ubbe
palmerjrusa
Member
I have an AOR LA380, an earlier iteration of the LA400 (you're right it is expensive), but it's an excellent wideband loop antenna and is very effective at nulling out noise.
What is the bracket shelf you have there?
It looks adjustable.
kg4zqz
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i could use an LA380 in my situation there, but could only find a used LA400 (lucky me!)... i never thought there was such a thing as a 'magic' antenna, but i am astounded by the performance and features..
the bracket (monitor stand) was a lucky find off that big S. American river: "Monitor Stand with Hub, Klearlook Foldable Monitor Riser with USB Ports and Type-C Port 24 W Width Adjustable Desk Organize Computer Stand Compatible with iMac/Surface Studio/Dell XPS 27"
Willy_Pete
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If you are using the standard Icom all-wart power supply - well they're known to be noisy. Try connecting a 13.8V linear power supply - the type that HAMs use - or else a 12 V car battery. If using a battery, you could also try turning off the mains power if possible - that should give you an idea where the noise is coming from before you race off spending $$$ on Antennas.
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