• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

SDS200 My 2 cent test on hum

bravo14

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
3,382
Location
#850Strong
I’m not sure if this thread be closed or not. I’m doing a two cent wedge test. I sent this unit in twice and still get that hum and I was thinking yesterday to try put 2 copper pennies in. About 30 mints ago I decide to try it. Before I did this I tried the audio off setting tried each one hum comes and goes this is before the pennies try test. The black cover was a little tight to close i did manage to get closed not messing it up.

DFE4F027-8A1B-470C-AFDC-A27A0446FA8B.jpeg
 

bravo14

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
3,382
Location
#850Strong
So far no hum within 20 mints. I do notice a small bump where the pennies are at. I may have to try find smaller ones.
 
Last edited:

kruser

Active Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
3,114
Location
St. Louis County, MO
So far no hum within 20 mints. I do notice a small bump where the pennies are at. I may have to try find smaller ones.
How do you plan on holding them in place so they don't short out the entire radio?
Relying on the pressure of the housing alone to hold them in place is asking for disaster!
 

bravo14

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
3,382
Location
#850Strong
How do you plan on holding them in place so they don't short out the entire radio?
Relying on the pressure of the housing alone to hold them in place is asking for disaster!
Where the uniden part goes in I went left of it I didn’t wedge them in hard just where it stopped the metal flat gray cover held them in place. Will it short the radio out like that? The pennies are not touching the main board.
 

frazpo

Member
Joined
Jan 14, 2007
Messages
1,355
Location
SW Mo
The fear would be as you move the scanner and manipulate the casing the pennies will slide out and yes, short out the solder points on the pcb. You are providing more ground. If you want to go this route buy some copper grounding tape to work with. It has s sticky side and you can create something that can be taped on place. When I was experimenting I wrapped pieces of tin foil with the copper tape and taped it In place. More or less doing the same thing you are doing with the pennies. The way to rid the hum completely and permanently is to remove the lacquer from the mounting holes on the display pcb.
 

bravo14

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
3,382
Location
#850Strong
@frazpo where did you get the tape at? I ordered mine from amazon. I had roll of it til I got displaced last year from a major storm.
 

frazpo

Member
Joined
Jan 14, 2007
Messages
1,355
Location
SW Mo
There is a solid fix for the hum. If I were you I'd call uniden and see if they are offering the fix yet. If you lived close I would offer myself.
 
Last edited by a moderator:

bravo14

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
3,382
Location
#850Strong
There is a solid fix for the hum. If I were you I'd call uniden and see if they are offering the fix yet. If you lived close I would offer myself.
On other thread that was closed uniden has no fix yet. Uniden put the part in and still humming.
 

N9JIG

Sheriff
Moderator
Joined
Dec 14, 2001
Messages
4,024
Location
Far NW Valley
I’m not sure if this thread be closed or not. I’m doing a two cent wedge test. I sent this unit in twice and still get that hum and I was thinking yesterday to try put 2 copper pennies in. About 30 mints ago I decide to try it. Before I did this I tried the audio off setting tried each one hum comes and goes this is before the pennies try test. The black cover was a little tight to close i did manage to get closed not messing it up.

View attachment 75141
US pennies minted from mid 1982 thru now are actually copper-coated zinc, I would expect that the copper coating could wear off eventually.

Pennies minted thru mid 1982 are 95% copper alloy (the rest is tin and other fillers). I don't know the electrical properties of zinc and how it might affect things but I would expect better results with cents with 1981 and earlier mint dates.
 

dougjgray

Member
Joined
Mar 8, 2003
Messages
455
Location
Englewood CO
I would find the sure fire fix on rr not sure what thread but I did seem to work for people that did the fix and call uniden and see if they will do it for you. Print the instructions and send it to uniden. My 200 came with the part and just hummed until it warmed up. I rolled up some copper tape and put it above the part to snug it up and no more hum. I didn't have any issues with uhf or vhd compared to my 436 the 200 might even be better. Except when I have the network connected then there is so much noise vhf and uhf are not monitorable. Maybe they make sheilded network cables
 

kruser

Active Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
3,114
Location
St. Louis County, MO
They do. Even though the SDS200 LAN jack is not shielded, using a shielded LAN cable similar to this one may help.
I'm not certain but the hum introduced over a LAN connection almost sounds like the same hum one can get from ground loops.
I only heard it with one computer but not the main computer I use with my SDS200.

I just looked into the LAN jack on the SDS200 and it is all plastic so it would not ever connect a shielded Cat5 or higher cables shield to anything on the radio end. It may still be worth a try though for anyone getting hum over the ethernet connection.
I also thought I saw an optical isolator for ethernet that you insert in the cable run. The bad thing about it was that it needed power on each end! I think it was made more to protect ethernet ports from voltage spikes and such.
 

dougjgray

Member
Joined
Mar 8, 2003
Messages
455
Location
Englewood CO
I don't notice a hum but on vhf and uhf it stops on half the channels with noise breaking the sqelch. Like railroad and air bands not as bad on uhf but not to much to listen to on uhf except dmr
 

kruser

Active Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
3,114
Location
St. Louis County, MO
I don't notice a hum but on vhf and uhf it stops on half the channels with noise breaking the sqelch. Like railroad and air bands not as bad on uhf but not to much to listen to on uhf except dmr
I think that's a result of the wide open front end used by the SDR TV Tuner chip.
Setting the Global filter or whatever type filter you are using for the channels with open squelch problems to Invert may help. Invert does attenuate the signal some so weak signals may be lost but it does also tighten up the tuner chips front end filtering some so adjacent channel interference may not be as bad.
These type problems may also be resolved by using the IFX feature.
 

jjbond

Banned
Banned
Joined
May 2, 2003
Messages
401
Location
Phoenix, AZ
[
I don't notice a hum but on vhf and uhf it stops on half the channels with noise breaking the sqelch. Like railroad and air bands not as bad on uhf but not to much to listen to on uhf except dmr
Yup, you end up "avoid"ing every frequency, while searching, even with external antenna.
 
Top