Adding a tone/noise filter to any radio.

[@rallypoint1]

Works great! Did it to a Cobra 18 ST II. That radio picks up everything. This poor mans hi-cut made it bearable. It’s just a spare radio but sounds great now.

[@andrewrudlang2785]

Awesome and really well explained, thanks so much going to make some of my cheaper radios a bit more bearable with this!

[@andrewrudlang2785]

I did it! It totally worked on my cheap Uniden Pro505XL! 0.10 uF ceramic I had from a kit cut off a big portion of the most annoying high-pitched static, thanks so much for this tip!

[@straightpride451]

I love your videos Mike, you are a very good teacher.

[@nxesr]

Does the CRT-9900 have the capacitor that you're saying? I've used the Hi Cut on the radio and seems to be doing fine or can I still go ahead and make the change?

[@trevorflynn1520]

What could it be if the volume just goes to the highest setting by its self could u help me fine this please.

[@paherbst524]

Would it have a similar effect to have the cap across the power lines?

[@577buttfan]

Na that's more for engine noise.

[@EvolvingNaturally]

Thanks Mike. Any Ideas for fan/Engine noise? Maybe some 3.3KuF Cap. across the power leads? I am using a President Mckinley. Some of the whine gets through even when the radio is squelched with the ASC and the normal squelch. It's like the audio circuit is acting like a receiver .

[@philphlint84]

Is that similar to hi cut external speaker which basically tags the capacitor legs to each speaker terminal on back of speaker audio cone eliminating the variability put into permanent hi cut

[@cbGamer481]

how fo i fix it ????? running a pure sine wave 3000 watts inverter for a 110v maco300 i dont know what to get first for a base station

[@adamhannah5078]

What's the level of capacitance the new President CBs use in their HI-CUT feature? I know the "HI-CUT" feature in the President Johnson II USA has a good overall sound. I would like to use that level of capacitance in my Cobra 29 and 25. Thanks.

[@mikesradiorepair]

The "Hi-Cut" feature in the President radios is microprocessor controlled through opamps.

[@adamhannah5078]

These type of mods are nice to remember. Pretty much anyone can do it, and the cost is a few cents to free if you have old parts hanging around your parts cabinet, or know a local tech who might just give you one!

[@adamhannah5078]

Haha, doesn't sound so simple to me. I think I will just do a side x side comparison with different capacitors. Shouldn't take too long, regardless. Thanks for reply.

[@mikesradiorepair]

No it's not. They use dual opamps in unity gain configuration. It's a RC (resistance/capacitance) filter at the input of the first stage. Out through another RC filter network to the input of the second stage and then out. Using the opamps in unity gain means the output of the opamp is at the same level as the input. They are using it basically to counteract the losses in the RC filter.

[@misterhat5823]

Four things come to mind: 1. One of the other two connections on the volume control will often be ground. If you get the wrong one, it'll be a high boost. 2. Tube radios will probably need a smaller capacitor than a solid state radio. 3. The amount of high cut will vary with the volume setting and there may not be any high cut at full volume. 4. Op-amps can get very upset (and oscillate) with a capacitive load on the output. Oscillation (which may be above the audio band) may occur a full volume if the volume control is driven by an op-amp or IC with similar internal circuitry. Adding a small (100 ohm or so) resistor between the capacitor and wiper should cure this.

[@kq4ccm_kevin]

Will you make a widen out revive video?

[@Fox250R]

Can this be done to a Stryker 955? Thank you

[@ramazanayten3758]

hi, i am using the rrd-102v2.0 radio module, now i am doing a project, for example, how can i control a radio station empty interference sound. I need to check, if there is a parasite, I want to have it checked with commands such as do the following, otherwise do not. //example if(noise==noise) { //bla bla bla } else { //bla bla bla }

[@raymondwarceneaux7423]

Is there a way to get rid of that noise 100% completely??????

[@577buttfan]

Use the squelch and clamp it out.

[@FUNKLABOR_DL1LEP]

go with volume to zero, you will hear nothing

[@clems6989]

We used to call this a "False tone control"...just limits the bandwidth of the audio...

[@blueelectricfusion]

Can a variable capacitor be used for this instead of an array bank of different values of capicitors w/ patentiomitor?

[@mikesradiorepair]

You could but it would never fit in the radio. To get a variable capacitor with values this large it would be very large.

[@cruisevideo1]

Will this eliminate PL tones from scanners?

[@user-su5sq5ib3i]

What about doing a parallel rc circuit and installing a potentiate? that way you can blend in how much filtering you want to use. Would like to see you back Mike

[@michaelhall3568]

Great info Mike thanks

[@rickjames2938]

Now I'm new to can radios so this might sound dumb but does this limit the distance the radio can hear? Or just limit the unwanted noise?

[@rickjames2938]

Cb radios, excuses the auto correct.

[@mikesradiorepair]

This is added to the demodulated audio circuit so has no effect on the receive sensitivity of the radio. It is a low pass audio filter that filters out high frequency audio content which has the cutoff frequency limit set by the value of the capacitor.

[@darwinhigginbotham250]

Isnt this the same as a Noise Blanker switch?

[@mikesradiorepair]

No. The noise blanker circuit is used to remove noise created by things like vehicle engine ignition systems. Short duration impulse interference. The noise blanker circuit actually (in a nutshell) shuts off the receiver during the impulse, that's why it's called a blanker. It blanks the audio during the duration of the impulse noise. It happens so fast the human ear/brain don't even know that the audio shut off and back on.

[@joevogelberger9922]

Nice! Thanks, Mike!

[@josephcote6120]

I imagine putting the cap across the volume control end to end would have a very similar effect. High frequencies bypass through the cap and never hit the wiper.

[@martyham10]

This makes sense to me... go for it...

[@tyrellmiller778]

excellent video

[@radioguy19510]

Do you get paid by the word?

[@JnJTrueOutdoorAdventures]

Nice video!! Thanks for sharing that information about the receive audio. I have a question, I purchased an Alinco DX-SR8T HF radio new back in September 2017. The guys that I talk with on 80 Meter band told me that the TX audio is awful. Basically they said it has to much highs and no lows in the audio. Of course I ended up purchasing a used Yaesu FT-757gx and they said that it sound more like me. My question is, would something like this work on the TX audio section of my Alinco?? Another friend had also bought an Alinco and had the same issue with his transmit audio. He tried many different mics and still no lows. I was told or read that the Alinco DX-SR8T was designed as a DX rig and that was the reason the circuit was designed not to pass mids or lows, just highs, so you could be heard in a pile up. Any information would be great!! Thanks again for the video, and I enjoy watching your videos. Juddie WD8WV

[@bucktadlock5258]

How do I get in touch with you for getting work done,

[@jackson4861]

You don’t, I’ve tried many times, he always ignores me too. Really annoying.

[@PapasDino]

I guess P.T. Barnum's observation applies to folks having a "super-tune" mod done to their radio!

[@adamhannah5078]

Yes! Definitely one of those "Caveat emptor" type of situations.

[@kevinkelley3657]

I really enjoy your videos, everything you do to radios makes sense. Thank you. Could u be an undercover ham??? 73

[@radioaktiv7841]

Nope, just someone who knows what they're doing.

[@uhfnutbar1]

i love you man :) where was youtube in the 80s and 90`s , cb dead now in Canada,,, thy allways say there a come back but not really :(

[@martyham10]

Are you sure about that? History has a way of repeating itself...(I think CB WILL be back)

[@cannadaincowboy]

I watched the video again and realized I missed the point of him saying not to use a polarized cap.I used one and it took all the volume and noise away but can't here talking.

[@williamcolvin3609]

I was wondering about those Ceramic Capacitor Kits - because of their size,take a 15nf for instance that was like 3/8 of an inch and a good 1/16 thick green capacitor is being replaced by like 3/16 x 1/32 thick small orange capacitor they claim is 50 and some even 100 volt rated. So I figured they were junk and tried to find something better sized to what was installed.

[@mikesradiorepair]

Haven't seen a 1uF or larger SMD ceramic capacitor have you, they are tiny . With today's technology they can make parts a fraction of the size of older parts.

[@williamcolvin3609]

So these 1W Resistors with the smaller leads are actually 1 Watt quality and safe to use. I purchased a lot of parts and would not use them because I did not trust them blowing and ruining a radio. I was watching your other video on the Madison and I have radios where the resistors on the Voltage Regulator Board have burned through the boards - LUCKILY the radio still works when connected to an external regulated supply.

[@blueelectricfusion]

Omg! Love it! Hey Mike how do I send you a stack of radios for repair? I have ic-7000 icom, 2x yeasu, 2x cobra 148gtl philipino radio's that need to be gone through and made right once again. And some nifty mods like this done.

[@craigwall9536]

God DAMN that was long-winded!

[@dougburdin8893]

Another fine lesson Mike thank you for sharing your knowledge with us! Oh who is Mark?

[@williamcolvin3609]

The maker of the Frequency Expansion Kit that Mike installs in radios - I think he can make one for about any radio,but Mike or one of the AUTHORIZED Distributors has to install for it to be warranted.

[@pep1dog1]

I have a remote speaker with a noise switch so I am assuming something similar can be done at the speaker

[@samiam5557]

Cool Mike thanks for sharing your tip, I'll give it a try on one of my car rigs.

[@624radicalham]

Cool party trick! Seriously this is something I'm definitely trying

[@loadhauler5301]

Good vid :) Just subscribed. Getting ready to get a new rig. It comes with a C.B.... Do you tweek. and peak ? I'D like to send you the radio. Let know. Keep teaching :)

[@jefferybernard4800]

That was a good

[@ademiltondasilvaleite4381]

You have to show in the diagrams what you're doing, who doesn't speak English doesn't understand

[@zooyawk4526]

👍👍👍👍👍

[@0002ken]

Why cant radio guys get to the point

[@paherbst524]

Will this make a difference on the squelch level / s meter?