• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

Kenwood Analog repeater background noise in certain area of coverage where there was none before.

Frmn85

Member
Joined
Jun 3, 2022
Messages
37
Hi fellow members,

I recently ran into a static issue in a certain area of a small facility that wasn't there before unitl after i performed measurements and made a minor increase in watt output. For the moment and I cant wrap my head around this. Maybe anyone here can offer some guidance.

The issue is a noticeable increase in static at a certain area( next to dispatch desk) that was apparently not there before until right after I checked measurements and swept the duplexer, and feedline. I increased the output power by .5 watts but reverted back after the issue came up in hopes to restore everything as it was before I came on site.

The static behind the audible communications is said to be like water and static mixed together. It is only heard on the downlink around the dispatch desk.

I used a VNA to sweep the area and only found a strong adjacent interfering signal about 2 MHz away ( to far away to cause issue right?). everything else was with in the noise floor. DL of repeater was at -95 or stronger ( good for analog) . No broadband noise of any kind was observed.




Below are some details.

The repeater is a conventional TKR840- 5 watt output and coupled with a BpBr Bird Duplexer and a single antenna.

Output of the repeater from duplexer to feedline is 2 watts.

Both are tuned to the best of its ability to meet their budget expectations. I want to note that
everything worked well after install, it is when i came back to check readings and made an attempt to optimize the system did things change reverting the minor changes did not cause the issue to go away.




Thanks for any guidance on this.
 

RFI-EMI-GUY

Member
Joined
Dec 22, 2013
Messages
7,039
Can you test for desense?
Where is the repeater antenna located? Any electronics nearby?
Check the connections to duplexer, antenna, repeater.
 

wd8chl

Member
Joined
Apr 4, 2007
Messages
328
Look for things that changed in or near that location, like a new computer or monitor, alarm equipment, or really anything electronic. Modern electronics generate noise. Computer networks are the worst. Very noisy.
I doubt there is an issue with the repeater. Oh, and to notice a difference in coverage, you need roughly a 3dB change. That means twice. If you're running only 2 watts, you would have to go to 4 to notice any change.
 

a417

Active Member
Joined
Mar 14, 2004
Messages
4,669
If you disconnected coaxial fitting when making measurements, that should be checked.
This.

That post reads as "It was fine till I touched it", and the point of order should be going back with a fine toothed comb to every component you touched. Something was disturbed, and the action of plugging / unplugging / moving / jostling is the primary causal factor here.
 

Frmn85

Member
Joined
Jun 3, 2022
Messages
37
Thank you for the responses.
I sniffed the area for noise with a VNA and nothing came up in the area of interest. I will look into the duplexer tuning again and associated cabling next opportunity.



Hopefully it solves the issue.
 
Top