What the noise blanker does in your radio and why yours probably isn't broken.

[@nickjones8702]

Best Radio repair man, fine my Styker955 alignment right !!! Thank you Mike! 😊

[@ComputerLearning0]

Excellent video explaining a really great feature and why you might hear a difference when using it versus not hearing any difference at all. You're the best, Mike.

[@lesjones5684]

He’s the best 😅😅

[@frankstern4841]

Why is the receiver in this radio so noisy without the antenna connected to it?

[@misterhat5823]

The gain is the highest with no signal and it's amplifying its own noise.

[@mikesradiorepair]

As Mister Hat said with no incoming signal the AGC circuit is going to have all the stages turned up to maximum. Once a signal is received the gain of the stages is lowered. The higher the incoming signal the less gain there is. Also the volume was turned up really high at several points in this video, up the whole way in some parts.

[@raunchyNO]

@@mikesradiorepair there are scientists that say that you actually hear the big bang and the residual noise from that moment.

[@frankstern4841]

I despise radios with a noisy receiver alignment. Thank your for your answer.

[@mikesradiorepair]

Yes, it's called the CMB or CMBR for cosmic microwave background radiation. Was discovered by Penzias and Wilson of Bell labs in the mid 1960's.

[@bblod4896]

When the points are closed, they completes a circuit that applies power (12 volts) to the primary of the ignition coil. When the cam on the distributor opens the points (the condenser helps protect the points from some of the arc) the magnetic field in the ignition coil collapses through the secondary which creates a high voltage. The high voltage goes from the coil through the high voltage wire to the middle of the cap located on the distributor. The rotor directs the high voltage to whichever plug is supposed to fire next. The rotor only has physical contact with a cap in the middle. There is a small gap between the end of the rotor and the cap, that is where ignition noise is created.

[@rickvia8435]

Yep, any spark-noise from the spark plug is contained (shielded) by the cylinder head and engine block. The distributor cap is where most of the impulse noise escapes. Resistor wires limit the current flowing between the gap of the rotor button and the distributor cap electrodes.

[@injoelsgarage3934]

Mike thank you for your time and sharing with us, great explanation of the noise blanker. Joel

[@rickvia8435]

Yep - the NB circuit basically "blanks" out the receiver for the period of a short-duration impulse spike. They taught me that the "background noise" heard in an unsquelched AM/ SSB receiver was actually "thermal noise" created when any electrical circuit is active. With no antenna connected, each stage of the receiver introduces thermal noise into the signal chain and processes this as a "signal": It (1) amplifies it - RF stage, (2) mixes it (the mixer also gets thermal noise from the IF stage), (3) detects it and (4) the audio stages amplify it into the noise heard in the speaker.

[@jacob2483]

Thank you for your knowledge, excellent video!

[@peternewman958]

Great video Mike, your not the only person who gets asked that question about the Noise Blanker!!!! It’s probably the number 1 thing people ask me also. Very good explanation and now I don’t have to explain it any more they can just watch your video mate!!!!

[@travistabuas5706]

Great video I will be sending you couple three radios for repairs in a couple of weeks

[@BoB4jjjjs]

That was spot on in what a noise blanker does and I think everyone has has a car go past a TV with the noise interference and even the clicks affecting the picture. The demo at the end showed what it does perfectly.

[@eddieslittlestack7919]

Studying for my tech. ham radio license, this was helpful. Thank you. Thumbs up sir!

[@lesjones5684]

Don’t lie 😂😂

[@davidmartin123]

The noise blanker in my ICOM 746 isn't broken - it just doesn't work very well. Pressing the NB button doesn't eliminate the transmission line spark-gap type noise that's cropped up in my neighborhood recently. It instead chops up the signal and reduces the noise only slightly. But the noise blanker algorithms in newer radios and even in the cheap SDRs running SDR# or SDRUno software (with adjustable NB thresholds) work great to eliminate that same transmission line noise completely.

[@Darrell_Coquillette]

You did a great job explaining that Mike! Tnx

[@user-su5sq5ib3i]

Thanks for the explanation Mike

[@porongoscasantero8768]

Excellent radios audio wise to

[@Stover159]

thanks mike. love your videos and love these little quick and to the point videos explaining things. i kniw myself and others would love for you to explain how and why every function/circuit in a radio works...thanks keep up the good work.....

[@royd.9609]

Very informative!

[@kriptyn56]

Aloha Mike, love ur videos just wanna say thanks for sharing ur knowledge...

[@timmygilbert1371]

Great video Mike , i consider myself fairly decent on cb knowledge but had no idea how the NB actually works and is meant for .

[@renegadebt1374]

My NB stops my neighbors electric fence from coming through..

[@ovidiuovidius]

NB & ANL is very very important for cb radio

[@MickeyD2012]

CB operators like ANL? Figures.

[@k.c.lejeune6613]

You little box creates sounds like when astronomers convert the "pulses" of Pulsars in space into sound, specifically millisecond Pulsars.

[@allthegearnoidea6752]

Interesting bit of test gear. Never seen that type of test before. Great video Mike. PS stinking of gear oil!

[@73superglide62]

Great info

[@walterathow5988]

always like your videos

[@johncundiss9098]

QUESTION ! ! ! Got a Rigol4102 signal generator with noise generator, this noise is not blanked, I suspect this noise is not the "right type" of noise? Have had trouble doing alignment on radios. Have restored a ts-530, ts-940s, and an ft-980. Show us how to make the box? The ts-940s works. the ft-980 works but has a "slow to recover" type action to it. P.S. Use ds-815 spectrum analyzer, MSO 4000 scope, dm3068 DMM. Seeking a better stand alone frequency counter and seeking a way to do SINAD measurements, homebrew of sorts perhaps. Ugg, more equipment to get/build. Actual RF sg gen wanted as well. Sorry for the rant. 73's.

[@justinruth9729]

Notch ..filtwr for pulses ...it's mainly for mobil applications...

[@thestonerguy5276]

Nice explanation and video! I don't know if you've worked on the old Alinco DX-70 at some point, but I owned several during it's run and while they had a great display and xmit audio, the NB sucked. Not only would it not tackle ignition noise, but when turned ON, it actually injected a lot of noise of it's own into the receiver, making it a terrible choice for mobile operation.

[@lesjones5684]

Cobra 🐍 138 xlr 😢😢

[@la7dfa]

Noise blankers should be adjustable for best control. In my TS-590S I have timing control for NB1, NB2 or both. They are all useful for various kind of noise. In my case its mostly static noise during hail and winter storms.

[@billybassman21]

Why do you get more bleed over on some Cobra radios when the noise blanker is on?

[@danz1910]

thanks

[@graziannycarvalho8091]

OLA AMIGO VOCE TEM O ESQUEMA DESSE CIRCUITO DA CAIXA QUE GERA O RUÍDO.... GRATO

[@mikesradiorepair]

kzbin.info/www/bejne/fXOQiaisptpqbqM Correction to the schematic. Pin 7 needs to be attached to ground.

[@davidcarter9322]

My uniden pro 538w picks up all the car electrical noise. It doesn't have a NB or ANL switch so I use the squelch and RF gain to tune it out. Unfortunately that makes for lousy RX sensitivity.

[@mikesradiorepair]

If it's a modern car join the party. All the noise from the vehicle computers is horrible in some of my newer vehicles. I installed a Powerwerx line filter in those vehicles and it pretty much eliminated it. powerwerx.com/dc-line-noise-filter-powerpole-connectors

[@W-733_KWX]

Stryker's supposed to have a better NB compared to the other nowadays "10m" rigs, do you agree Mike ? This one seems to work darn well !

[@adammeece3678]

I need to know how to get you to possibly rebuild a couple Cobra 2000 GTLs for me. Im new to the CB world and am excited to learn all this stuff!!

[@mikesradiorepair]

Just add @gmail.com to my KZbin user ID to email me.

[@robschlotterbeck2566]

Can you find the circuit diagram on line??

[@mikesradiorepair]

Honestly I'm not sure. I'll make a quickie video later this evening showing how to build one. Might not get uploaded until tomorrow.

[@robschlotterbeck2566]

That would be great Mike!

[@robschlotterbeck2566]

I’m working in Gettysburg PA until tomorrow then I’m driving back home to Indiana for surgery Tuesday. I can spend some recovery time with a bread board Wednesday. I assume that the heart of the device is a 555?

[@mbutts1139]

@@mikesradiorepair That is something I don't have for my bench, that would be awesome

[@lesjones7019]

Buy a new radio.

[@michaelcasson5789]

I have a tram d201a and a golden eagle 4a that needs work... wandering how long before you will be able to work on my radio?

[@antoniosherryalmeida1505]

Hi, I have Cobra 2000 GTL I would like to get a Channel King board install. Would you have time to do it ? what would it cost and how much time would it take? Please let me know .Thanks

[@thecodfather4425]

its the hicut that cuts down the hiss.

[@mikeevans4691]

Hi. How would I get in touch with u to be able to send u a radio for refurbish. Thanks for your time.

[@squireca]

Have a question I'm hoping someone here can answer. I purchased a Dynascan Cobra 29 23 channel cb I am hoping to restore. I got the sams photofact cb-56 for this radio but am A bit confused about the electrolytic capacitor list. For some of them there are two different values shown, such as c46 10mf at 16v and 10mf 10v. Another is c51 1mf at 50v ans 1mf at 16v. There are several like this listed. Should I just go with the higher v caps? Thanks for any replies.

[@mikesradiorepair]

When in doubt go with the higher voltage.

[@bossman-91]

how much do you charge to fix i got a cobra gtl 2000 i need worked on

[@burmanspangler9393]

Hi, How can I get in touch with you ?

[@k9usa149]

any one know how to get a hold of Mike to do work on radios? Never get an answer from him via e mail?

[@Tomahawk-415]

I meant like rg8u? or 213u? or in general what is the best for the cb band 75' to 100' run

[@mikesradiorepair]

As I said before the best cable is the best you can afford. In general the more it cost the higher the quality .

[@Tomahawk-415]

Hey Mike I'm putting up a 40-foot Tower at my house with a 24-foot solarcon IMAX 2000 on it what would be the best coax to use, about 75 ft will be needed, cb band thanks

[@mikesradiorepair]

The best coax for any application is the best you can afford. The higher the quality of the coax the more it cost. You can get crazy and spend thousands of dollars on large diameter premium hard line or use something more reasonable like LMR240 or LMR400.

[@alanwilson2201]

Are their any radios on the market that are AM only with variable talkback and echo? I’m not interested in sideband or anything extra. I’m looking for a box stock AM radio with variable talkback and echo that I can order or pick up locally......

[@mikesradiorepair]

Honestly I'm not the right person to ask about that. I don't sell radios, I only do repairs. The best people to ask about something like that would be a shop that sells radios. They are going to have a better idea of what is currently available that would meet your requirements.

[@alanwilson2201]

In your opinion is there a particular radio that can handle the shock and vibrations of being in a dump truck?

[@mikesradiorepair]

Any modern radio that uses surface mount components is going to be more resistant to damage from shock and vibration. One of the biggest problems in high vibration environments is bad solder joints. Older through hole design boards are more susceptible to solder joint failure because the parts are hanging off the board by their wire leads. Surface mount parts have no wire leads, they are soldered directly to the surface of the circuit board.

[@porongoscasantero8768]

Bearcat and 148 can make the same audio

[@quaildogusa]

I have a 2020 Dodge Ram Hemi and I'm getting ignition noise. I'm thinking it's spark plug noise.

[@mikesradiorepair]

Probably not the type of ignition noise you are thinking about. You probably don't have spark plug wires. Most vehicles these days have coil on plug packs, there is no spark plug wire in most cases. There is however a bunch of other electronics in modern vehicles that cause interference on HF. Proper grounding, connection directly to the battery and judicious application of ferrite cores/beads to power and coax cables can greatly attenuate this interference.

[@quaildogusa]

@@mikesradiorepair Thanks for the reply. I do have the power grounded to the battery terminal. Someone suggested that I should move it off the terminal to the chassis ground.

[@jordanhowell3870]

Yeah but you will still hear it right if somebody talking is coming in right?

[@mikesradiorepair]

No, it works on fast rise time pulses. It will still blank the sound if a pulse triggers the circuit while someone is talking but you will never hear it. The amount of time the audio is "blanked" or muted is so short our brain can not hear it. Same effect as a flashing light. Flash a light fast enough and we can not tell it's flashing, it looks like a light that is on continuously but it can be turning on and off 30 or less times a second. Our brains are VERY slow.

[@jordanhowell3870]

@@mikesradiorepair thanxx man !

[@Hydrostream1972]

What's the difference from 500 ohms. to. 1000ohms. .mics? ??.. mike from minnesota. ....question. . 5watt. dead key. to much.??? 20 watt peak swing to much..???? on midland 5001z. radio. ...

[@paulb.131]

Mike..is there any way to get in touch with you?

[@mikesradiorepair]

Just add @gmail.com to my youtube user ID.

[@bblod4896]

Can I assume a square wave generator will work?

[@mikesradiorepair]

No, it needs to have a very fast rise time and be a very short duration pulse. I'll make another video this evening with a schematic and demonstration of the circuit. Might be tomorrow until it gets uploaded.

[@bblod4896]

@@mikesradiorepair Thank you very much sir and have a great evening.

[@GNRFreak69]

@@mikesradiorepair Awesome video. Looking forward to the schematic.

[@lesjones5684]

My noise blanker doesn’t even work 😂😂

[@KeiranR]

you know it works when you get that type of noise...

[@mathewkromeo2934]

Hello. I am looking at a never used Royce 604 in box from 1977. I don't know much about Royce. Good radios? Very clean. $50. I have a brand new Cobra 25 LTD Classic, mic mounted on the front, China made. I bought the Cobra rather impulsively but wanted something vintage. Was Royce a good brand?

[@mikesradiorepair]

Royce was a good manufacturer. They did things a little different than many other manufacturers. The 604 is a good example. It has what I would call a "one chip wonder". Most of the receive circuit to include RF Amps, mixers and IF stages are all done on a single IC.

[@mathewkromeo2934]

@@mikesradiorepair Thank you so much!

[@theflyingscotsman9902]

@@mikesradiorepair Hi , I have a Whistler 900 that was working and quit a few months ago . Sent it to a local cb guy and it is now dead ! Just lights up ! No audio and no transmit ! I dont know what he did but he offered me another radio for free because it quit while he had it ! Fair enough , but I miss my neat Whistler 900 ! Could you have a look at it ?

[@MM0IMC]

I found that the noise blanker circuits in these CB or "10m" radios don't work on SSB. Whereas on my HF radio, it works great.

[@casemcdonald2152]

You're mistaken about the brain not being fast enough. What's really happening is, the brain it's so sophisticated that it can compensate. Just saying.

[@JamesJohnson-ny3xz]

Cap It.

[@lesjones5684]

It doesn’t do anything 😂😂

[@jizomeovonsteelwind]

Now if I can only get rid of the engine whine that comes through my speaker, I'd be doing much better....

[@mikesradiorepair]

Are you sure it's engine noise? In modern vehicles it's not engine noise but electronic noise generated by the vehicles electronic systems that create a lot of the noise. If the noise doesn't change with engine speed then it's not engine noise. I have a fairly new car here that it took me a good bit of fiddling with to finally get rid of all of the electronic noise generated by vehicle computer systems.

[@jizomeovonsteelwind]

@@mikesradiorepair Thanks for the reply. It's an 88 pickup with older internals. I swapped out all of the "newer" in favor of an older setup with carb and HEI distributor. It does change with engine RPM, the high pitch whine gets louder as I hit the accelerator. When I'm driving it's almost impossible to hear above it. At idle, it's still annoying, but bearable.

[@mikesradiorepair]

Make sure everything has a good ground. You can also try sticking a filter on the power cord. These help in some applications.

[@jizomeovonsteelwind]

@@mikesradiorepair I have everything grounded with star washers a plenty, but I'll double check everything. Do you have a filter you'd recommend?

[@mikesradiorepair]

@@jizomeovonsteelwind powerwerx.com/dc-line-noise-filter-oemt?gclid=EAIaIQobChMIy8W_9ZbG4AIVwSNpCh0M1QJ_EAQYBSABEgJ7-vD_BwE

[@retekessradioamazon6255]

Hi MikesRadioRepair ,I have send you the email,please check, and give us a reply,thanks so much. PR15 radio