Pro-26 buzzing sound when scanning/searching

[jomjom79]

Hi there. Just got ahold of a used Realistic Pro-26 (90s model) that has a buzzing sound out of the speaker and earphone jack when scanning/searching. Im pretty sure there might be a bad filter cap in this and would like to get it fixed. However i cant seem to open it...

Ive read the service manual and it states that to remove the front and rear case just unscrew the 4 screws on the back. Ive done this but i cant seem to get it separated. It also states that to remove the top plate unscrew the spanner nut around the BNC connector. Is this necessary to get it separated as it requires a tool which i dont have.

I also noticed that the earphone jack only has audio coming out of the right channel. Is this intentional or is it a fault?

Thanks
John

 

[dave3825]

It also states that to remove the top plate unscrew the spanner nut around the BNC connector. Is this necessary to get it separated as it requires a tool which i dont have.

Sometimes those can be unscrewed uning a small pair of needle nose pliers or a small tipped slotted screwdriver.

 

[KD9KSO]

I've replaced cases on two of these scanners. The fit between front and back is tight even after removing the screws. Don't try to pry the case apart with a screwdriver, it will chew up the plastic. A wide, plastic putty knife with a sharp edge will help.

 

[tvengr]

Hi there. Just got ahold of a used Realistic Pro-26 (90s model) that has a buzzing sound out of the speaker and earphone jack when scanning/searching.

Are you using batteries or an AC adapter? There is a difference between a control channel or digital buzz and an AC hum.

 

[jomjom79]

Sometimes those can be unscrewed uning a small pair of needle nose pliers or a small tipped slotted screwdriver.

Tried that but its too tight. And i dont want to chew up the slots on that nut.

I've replaced cases on two of these scanners. The fit between front and back is tight even after removing the screws. Don't try to pry the case apart with a screwdriver, it will chew up the plastic. A wide, plastic putty knife with a sharp edge will help.

So you dont have to remove that nut on the BNC connector?

Are you using batteries or an AC adapter? There is a difference between a control channel or digital buzz and an AC hum.

Im using batteries. The DC adapter has negative centre plug which i dont have at the moment. Not without cutting and resoldering wires. The buzz is coming from the speaker/headphone jack and is not affected by the volume. Its really noticeable using headphones.

IS the Buzz there if you try the Weather channels ?

Yes. Its always there aslong the scanner is scanning/searching. No noise when its idle

Im from Norway. The buzz is not any transmission. Its a internal buzz made by the radio itself. Its only there when its searching or scanning. Its not there once it is idle, stopped on a channel or is receiving a signal.

 

[ecps92]

Hi there. Just got ahold of a used Realistic Pro-26 (90s model) that has a buzzing sound out of the speaker and earphone jack when scanning/searching. Im pretty sure there might be a bad filter cap in this and would like to get it fixed. However i cant seem to open it...

Ive read the service manual and it states that to remove the front and rear case just unscrew the 4 screws on the back. Ive done this but i cant seem to get it separated. It also states that to remove the top plate unscrew the spanner nut around the BNC connector. Is this necessary to get it separated as it requires a tool which i dont have.

I also noticed that the earphone jack only has audio coming out of the right channel. Is this intentional or is it a fault?

Thanks
John

IS the Buzz there if you try the Weather channels ?

 

[tvengr]

What is your city, county, and state? On which frequencies are you hearing the buzz? the PRO-26 is analog only. You will hear a buzz when receiving any digital transmission.

 

[KD9KSO]

It is not neccessary to remove the top if you are removing the front or rear of the case. The instructions are there if you want to remove the top plate to change out a pot or the antenna jack.

 

[ecps92]

What is your city, county, and state? On which frequencies are you hearing the buzz? the PRO-26 is analog only. You will hear a buzz when receiving any digital transmission.

Just caught in Post 5 , he is in Norway

 

[tvengr]

Just caught in Post 5 , he is in Norway

Thanks!

 

[tvengr]

Is it possible to post the sound so that we can hear it?

 

[crippledchicken]

Due to the age of the unit it's possible it's a bad capacitor.

 

[jomjom79]

Is it possible to post the sound so that we can hear it?

Will do that in a couple of days once i get a hold of a device with an actual audio input.

Due to the age of the unit it's possible it's a bad capacitor.

Yeah. I actually managed to get it open today thanks to KD9KSO using a plastic spudger. That thing was tight!

I was expecting at least some through hole components, however all the capacitors are surface mount. I dont really have the tool to check ESR on these things while they are in circuit however i did not see anything obviously wrong with them (such as leaking)

Did some basic contact cleaning on the connector that connects the two boards together and did some visual inspection of solder joints and such. Did not really find anything.

Not too fond of working with SMD components.. Maybe about 20 years ago.

Either the components are getting smaller or my hands are getting fatter..

 

[wtp]

 

[bearcatrp]

I have a Pro 26. Doesn't do any buzzing on batteries or wall wart. Suggest you get a wall wart to try. Took me a bit to find one but just google Pro 26 plug in. Got mine off of ebay.

 

[magicsax48]

Hi there. Just got ahold of a used Realistic Pro-26 (90s model) that has a buzzing sound out of the speaker and earphone jack when scanning/searching. Im pretty sure there might be a bad filter cap in this and would like to get it fixed. However i cant seem to open it...

Ive read the service manual and it states that to remove the front and rear case just unscrew the 4 screws on the back. Ive done this but i cant seem to get it separated. It also states that to remove the top plate unscrew the spanner nut around the BNC connector. Is this necessary to get it separated as it requires a tool which i dont have.

I also noticed that the earphone jack only has audio coming out of the right channel. Is this intentional or is it a fault?

Thanks
John

I have the same issue, who can repair my Pro 26 scanner

 

[rhodester]

Try here. Home Page

 

[tvengr]

Does the pitch of the buzz vary with volume?

 

[toploader]

Hi there. Just got ahold of a used Realistic Pro-26 (90s model) that has a buzzing sound out of the speaker and earphone jack when scanning/searching. Im pretty sure there might be a bad filter cap in this and would like to get it fixed. However i cant seem to open it...

Ive read the service manual and it states that to remove the front and rear case just unscrew the 4 screws on the back. Ive done this but i cant seem to get it separated. It also states that to remove the top plate unscrew the spanner nut around the BNC connector. Is this necessary to get it separated as it requires a tool which i dont have.

I also noticed that the earphone jack only has audio coming out of the right channel. Is this intentional or is it a fault?

Thanks
John

Would love an update to this post. Did you manage to fix the problem? And if so what was the issue. Did something need replacing.

Is this the same buzzing sound you had? Realistic PRO-26 Clicking / Buzzing [Video]

 

[tvengr]

Would love an update to this post. Did you manage to fix the problem? And if so what was the issue. Did something need replacing.

Is this the same buzzing sound you had? Realistic PRO-26 Clicking / Buzzing [Video]

181.25 MHz is the visual carrier frequency of analog TV channel 8. Are you using a digital to analog converter on an old analog TV?