Certainly an overlooked control in many cases. I’ve been renewing my interest in CW, listening/copying in the evenings. Using the RF gain control, AGC speed, and filtering built in to my TS590, I found that I could have beautiful ‘armchair copy’ by balancing these controls. As you say, there’s no need to amplify noise and these simple controls easily improve copy. Most people I know always keep the RF gain control full open. Thanks for posting.
Great video Peter. I was fortunate enough to have an Elmer show me the RF gain control the first time I ever operated (ran the club station for Winter Field Day here in the States a few years ago) and it really helped. This gives me some more things to think about for the rare occasion I get the chance to work the airwaves these days. Also, I must say I really do enjoy the intro music. Delightfully fun.
I just got my IC 7300 the other day. After hooking everything up I excitedly turned it on & what was the first thing I did ? Well, I cranked that-there RF Gain control WAY UP (like a crazed teenager who just got his Driver's license & stomped on the accelerator pedal just to see how much "Pep" his car has), just short of "Squelch". As a result, for days I had been Monitoring (Overseas Airline Traffic on 8.843 Mhz) - putting-up with that annoying "Pumping" effect in between Transmissions, with so much Noise. After getting fed-up with that, I studied the relationship among the three controls & started fiddling around on my own. The 1st thing I did was to turn the RF Way Down, then turned Up the Volume control to 12:00 - 1:00, followed by setting AGC to "Fast". Lo & Behold - as a result I finally "Scared" my Tranceiver into giving me the loudest, clearest Voice transmissions ever, with the lowest background Noise possible. And no more "Pumping/Breathing/Compressed sound ! I think I accidently stumbled upon what you are saying here in this video I just found today, which seems to confirm what I had accomplished several days ago. I just "Set It & Forget It" & "Leave It The Hell Alone" (happily). Thank you so much - your videos are extremely helpful & "Very Diplomatic" : In an exquisitely eloquent way only an Englishman can do. 73s.
Thanks for this video, I learned a few tricks I didn't know. Would you consider doing a series showing "best use", control by control? I am sure this would be useful to newbies, returners and revision for experienced people who set up by habit and may have forgotten some aspects. When people ask "how high is your noise floor", is that with RF gain down or up noticing it's effect on the signal meter?
I tend to set preamp & attenuator per band to basically accomplish the same thing, but also use the squealch control when in QSO's or Rag Chews (mostly on the lower frequency bands) to make SSB almost as comfortable as FM. I also use a Noise Reduction speaker, especially on the lower bands. Back when I was living where I could run 160m with a full size inverted L it was necessary, especially in the summer, even with a magnetic RX loop. Keep spreading the good word! 73's mike N4ONL
Yes reducing the RF gain control setting for minimum noise, is little understood these days by some hams and it certainly helps. Problem is the RF gain control has to be set to at least a quarter to nearer the half way mark, to obtain a meaningful s meter reading, and this compromises noise reduction . You would have thought by now, manufacturers of modern SDR rigs would have overcome this RF gain issue. I have found that by using an outboard analogue audio processor, which has compression, expansion and a limiter really can improve the signal to noise on even the weakest signals buried in the noise. My audio processor limiter, can be very useful for greatly reducing very loud static crashes, making it much easier on the ears to copy SSB signals. So the extra expense by having an audio processor, has certainly been worthwhile for noise reduction. Perhaps modern SDR rigs should have a built in receive analogue audio processor, what a great idea.
Hi Peter..Having (and this is embarrassing) never touched this control before, I’ve been using this technique since watching your video, and the difference in ‘ear stress’ relief is amazing, especially when switching from tx to rx..so once again, many thanks for your video and valuable advice…73..John..G4EIJ
When NC for a traffic net or checking in to a net, where I will be on a frequency for a while, I move the preselector filter so that my center frequency is at the edge of the filter passband, then adjust the rf gain until the s- meter deflection is just above the peaks of the noise. Much more enjoyable, and I can still copy the weaker stations just fine.
Hi Peter, This is an interesting subject and the funny thing about you using an IC-7300, is that this is the main "disappointment" in my 7300 (SDR) when I compare it to my IC-9100 (superheterodyne). On the 9100 I can reduce the RF gain so that the AGC does not "pump-up" the noise in the pauses of the speech, but the audio level from the voice is not that much reduced, resulting in a far better -perceived- SNR. As you mentioned: this makes listening so much more comfortable indeed. I have used this for years and still do .. on the 9100. On the 7300, however, it does not work nearly as good (I am still using v1.30 firmware, so maybe things have changed by now). On the 7300, reducing the RF gain reduces both signal (voice) and noise and this is because the AGC on an SDR receiver works "a bit" differently. It still works a little, but not nearly as effective as on the 9100. Setting the AGC to 'slow' has far better effect on the 7300, i.e. as long as the remote station keeps on talking :) Of course, as you will surely understand, by reducing the RF gain, you are not changing the SNR at all. You are reducing the level of the "pumping action" (your words) of the noise by the AGC. 73, PC1JB
As i explained, it is the absence of noise during AGC recovery that is the main benefit. It does work better on a suoerhet snd the modern Yaesu radios with superhet front ends. Thanks for sharing. 73 Oeter.
I'm surprised that with SDR, there's not a way to suppress noise *more* than the signal because the noise is going to be much more Gaussian and stationary than SSB (which is much more coherent, and not so stationary). I agree that by turning down the RF gain I have noticed it becomes easier to listen, but also agree unless you can separate S from N, your not improving S/N (or S+N/N).
I 100% agree my main complaint with my ic 7300 is a poor (putting it mildly) RF control. Making it almost unusable on noisy top band . The ftdx 10,ts590 ts 870 , even the ft817 outperforms the horrible ic7300RF control.
On IC 7300 In the Audio screen, there are attenuation settings of 10 20 or 30 and the audio peaks go down accordingly. This is a different setting to holding down the P.AMP/ATT button and have ATT show up on the screen.
I found turning the Agc off on the 7300 was the best way to work with the rf gain control. Interestingly that method doesn’t work quite as well on the 7610. I keep the Acg on and adjust rf gain manually and with attenuation. I believe the 7610 has it’s Acg operating in a different part of the rf path and as such performs better as standard (and I’d agree with a that in practice too). Great video Peter 👍 thank you.
A very informative video on an interesting subjekt RF GAIN! [I was informed by an amateurradiocollegue about it!] Thank You Peter! 73s de Gunnar sm6oer
Good video, thank you. Question; is use of the RF attenuator function (such as on my TS-890; -6, -12, and -18 dB options), functionally the same as reducing the RF gain in terms of reducing 'heard' noise during pauses in speech on SSB?
I really enjoyed your video. I am a student and want to be an RF Engineer in the future. I have a question, sir, what if I add adaptive filters to remove noise that varies over time. This is an advanced DSP topic but it really will help to block background noise. Also, I can use a bandpass filter centered at a very narrow band frequency to remove noise if and only if noise frequency is not present in that narrow baseband signal. please clarify for me. I have just theoretical basic ideas, Should I go for experiments if it works. Thanks in advance.
Dealing with noise is a complex problem. DSP algorithms are pretty good but there is always a loss of quality. Bandpass filtering has the disadvantage of also filtering what you are trying to hear. I wish you well with your Electronics future and maybe you will be able to answer your own questions. 73 Peter.
I had heard of this before in connection with an old article on its use with Icom 756 Pro, Pro2, and Pro3. I found your video very helpful! But I wanted to ask a question: Is this procedure specific to Superhet radios? Will the newer SDR radios also be able to use this technique? (Maybe irrelevant, but I wanted to ask) TIA!
Minor counterpoint, with the controls adjusted so, one would likely not hear the extremely weak "Mayday" call in between the other station's sentences. LOL !!! 🙂
@@acestudioscouk-Ace-G0ACE yes. My comment was that a super hed does it better. The radio architecture is better build for that technique. Try it and see.
Unfortunately the RF control on the ic7300 is very poor . My ic 703 , ic 746 ,ic 7200 ic 781 is much much much better. The SDR ic 7300 sadly does a very poor job . But a do agree the RF control is my go to,to squash noise. DNR doesn't make up for a good RF control. However like i said most sdr radios I have Xiegue g90 and x6100 and ic7300 are poor when it comes to RF control . My somewhat low regarded yaesu ft-897 has a much much better RF control than the ic7300 ! On top band in noisy conditions the ic7300 is poor when it comes to RF control.
The RF Gain was designed to combat reciever overload not reducing signals to combat noise it just doesn't work. Why would you want to de sesitize your receivers why not just tackle curing the noise floor.
