TRX-1 Experiencing some distortion

[afdscan]

I have the TRX-1 and I have noticed that the local 800 Mhz trunking system is sometimes distorted. At other times it is very clear. This is on the statewide network which is a Motorola Type II SmartZone Omnilink system. Do I need to adjust the thresholds? They are currently set at 88 low and 95 high... This what was automatically set when downloaded from the RR database. If I do need to adjust them, what is recommended?

 

[darunimal]

Try 50-95 or 35-90 or 15-95

 

[budevans]

I have the TRX-1 and I have noticed that the local 800 Mhz trunking system is sometimes distorted. At other times it is very clear. This is on the statewide network which is a Motorola Type II SmartZone Omnilink system. Do I need to adjust the thresholds? They are currently set at 88 low and 95 high... This what was automatically set when downloaded from the RR database. If I do need to adjust them, what is recommended?

Are you in one of the Simulcast area's?

 

[afdscan]

Are you in one of the Simulcast area's?

No. I am not.

 

[afdscan]

Try 50-95 or 35-90 or 15-95

I'll try these settings and see what happens. Thanks.

 

[del1964]

I'll try these settings and see what happens. Thanks.

Lemme know how this works out. I may change my threshold levels

 

[afdscan]

Lemme know how this works out. I may change my threshold levels

I have changed the threshold settings to 15 low and 95 high. It seems that 90% of the distortion is now gone. ISP Districts 51 & 52 have zero distortion. County talk groups have some slight distortion (mostly an echo effect) occasionally. It is an improvement.

 

[del1964]

I have changed the threshold settings to 15 low and 95 high. It seems that 90% of the distortion is now gone. ISP Districts 51 & 52 have zero distortion. County talk groups have some slight distortion (mostly an echo effect) occasionally. It is an improvement.

Nice. I'll play around with that when I get a chance.

 

[darunimal]

He is on a Motorola Type 2 System not Phase 1 & 2, try turning off AGC Analog & Digital and DSP 72 or 74 or 76

 

[budevans]

He is on a Motorola Type 2 System not Phase 1 & 2, try turning off AGC Analog & Digital and DSP 72 or 74 or 76

FYI, Motorola Type 2 Systems can be Simulcast. It's not limited to P25 systems. In fact there are multiple Simulcast counties for that system listed in the RR Database. That's why I asked the question.

Regarding hearing echo's. That's usually the result of having two radio's in close proximity. Not a system or scanner issue. An example would be an officer on a portable standing next to a patrol car (both radio's same freq or talk group). Or two officers next to each other, both with radio's. If one transmits, you'll hear the echo from the others radio.

 

[del1964]

The whole state is transitioning over from Motorola to P25. Southeastern Indiana counties were the first to make this changeover recently (I know because I live in SE Indiana...haha) I noticed that suddenly my broadcasting feed with my BCD396XT went deaf. I hooked it up to update to RR website (it had been a while) and that's when I noticed they switched systems. RR database called the "original" Motorola and the "new" P25. So adjacent counties you live in in Indiana might be on the old system and yours under the new system and weekly updates from the database is the only way to keep up with it.

 

[darunimal]

Sorry budevans I didn't realize it was you, a lot are, but most don't have the actual LSM structure in the older architecture to utilize the different modes of transmission, and the typical FM discriminated voice decoder hasn't nary a problem with it.

Simulcast is a misused/overly used /misunderstood phrase with a deep base of inferred meanings, I responded by inferring the system types weren't the same, it's my fault for not explaining things better.

 

[afdscan]

He is on a Motorola Type 2 System not Phase 1 & 2, try turning off AGC Analog & Digital and DSP 72 or 74 or 76

Thank you. I made the adjustments that you suggested and there is a major improvement. Under the DSP settings there is also an ADC option that is blank and a DAC option which is set at -4db. Do I need to do anything with these?

Thank you for your help.

 

[darunimal]

0 and 0 (zeros) or +1 on DAC but zeros should work nicely

 

[AggieCon]

The threshold is for the control channel decode. I'm pretty sure it has nothing to do with voice.

 

[afdscan]

The threshold is for the control channel decode. I'm pretty sure it has nothing to do with voice.

That is interesting. I wonder why after changing the settings the distortion was gone?

 

[darunimal]

Bad injection equals bad decode hence why it works

 

[afdscan]

Bad injection equals bad decode hence why it works

Okay. That makes sense. I'm learning a lot from you guys.