SDS100 Images! (not pictures, RF!)

I am having a hell of a time with images and whatnot with this scanner.

Hearing things on frequencies I shouldn't, and overload issues.

Prime example I gave in another thread , local FD repeater on 453.7000 is showing up on 453.1625!

County I live in uses a pretty standard PL tone for most of the towns/cities. I just heard another department's repeater over my local PD's frequency on the SDS. My 785D, nothing. (On either). Hearing other mixes on frequencies without PL. Never had this with other scanners on my outdoor antenna.

Are other SDS-100 users having this issue?

I know about using the attenuator, but I shouldn't need to. The 536HP and it's predecessor, the 996XT never needed to use one for the selectivity. Hope this is something that will be resolved with firmware.

Why are you against using the attenuator? That's what it's there for, to be used when needed. You don't want to use your horn in your car, but sometimes you have to.

w1kne said:

I am having a hell of a time with images and whatnot with this scanner.

Hearing things on frequencies I shouldn't, and overload issues.

Prime example I gave in another thread , local FD repeater on 453.7000 is showing up on 453.1625!

County I live in uses a pretty standard PL tone for most of the towns/cities. I just heard another department's repeater over my local PD's frequency on the SDS. My 785D, nothing. (On either). Hearing other mixes on frequencies without PL. Never had this with other scanners on my outdoor antenna.

Are other SDS-100 users having this issue?

I know about using the attenuator, but I shouldn't need to. The 536HP and it's predecessor, the 996XT never needed to use one for the selectivity. Hope this is something that will be resolved with firmware.

Click to expand...

I had a similar issue during testing. I was advised to hold on the channel receiving the interference then FNC+7 to enable IFX. See if that doesn't help with your issue

Houk

Sent from my Moto G (4) using Tapatalk

jasonhouk said:

I had a similar issue during testing. I was advised to hold on the channel receiving the interference then FNC+7 to enable IFX. See if that doesn't help with your issue

Houk

Sent from my Moto G (4) using Tapatalk

Click to expand...

I will try that. I hadn't thought about it.

ur20v said:

Why are you against using the attenuator? That's what it's there for, to be used when needed. You don't want to use your horn in your car, but sometimes you have to.

Click to expand...

I shouldn't need it. I am not in an area of a lot of RF overload, especially on some of these I am getting. I know how an attenuator works, and what it does. Which is why I contest I don't need it where I am located. I sure don't use it on the 536 that was in this model's place, and had ZERO issues with this.

FYI, I moved your post to the Tech Support thread for better visibility.

w1kne said:

I shouldn't need it. I am not in an area of a lot of RF overload, especially on some of these I am getting. I know how an attenuator works, and what it does. Which is why I contest I don't need it where I am located. I sure don't use it on the 536 that was in this model's place, and had ZERO issues with this.

Click to expand...

That would be fine if the SDS100 was the same as the 536... but all they have in common is the manufacturers name.

ur20v said:

That would be fine if the SDS100 was the same as the 536... but all they have in common is the manufacturers name.

Click to expand...

I am well aware how all this works, again.

Thank you.

Back to the subject at hand. I noticed the IFX is frequency specific. This seems to happen pretty broadband across the UHF band.

I haven't noticed it with VHF or 800.

It's classic poor selectivity. I am assuming it could be fixed with the receiver firmware, as it gets updated. But typically SDR's have excellent selectivity which is why this surprises me some. As I said I am not in an environment with a lot of RF. In fact the UHF RF world here isn't extreme by any measure, and I am seeing this. I hate to see what happens in a dense RF environment. I could use the global attenuator, but then I risk other frequencies being lost in the field. And using an attenuator to resolve selectivity issues, is putting a piece of tape over a leaking pipe. It stops the leak but doesn't fix the issue. The 536 and SDS-100 are different receivers, (as was explained above), but the selectivity should improve with a newer model, not get worse.

If I am the only one having these issues, I'll have the unit exchanged with Uniden. But if others are , it would be nice to see a trend. I am sure the folks who work at Uniden would like to see such a trend, if there is an issue.

KevinC said:

FYI, I moved your post to the Tech Support thread for better visibility.

Click to expand...

Thanks Kevin.

Agreed and commonly it seems with the SDS in VHF when near higher powered repeaters. Did IFX work for your instance?

Houk

w1kne said:

Back to the subject at hand. I noticed the IFX is frequency specific. This seems to happen pretty broadband across the UHF band.

I haven't noticed it with VHF or 800.

Click to expand...

Sent from my Moto G (4) using Tapatalk

jasonhouk said:

Agreed and commonly it seems with the SDS in VHF when near higher powered repeaters. Did IFX work for your instance?

Houk

Sent from my Moto G (4) using Tapatalk

Click to expand...

I am waiting. I've hit a quiet window with the Fire Department on the one specific frequency I adjusted it on.

jasonhouk said:

Agreed and commonly it seems with the SDS in VHF when near higher powered repeaters. Did IFX work for your instance?

Houk

Sent from my Moto G (4) using Tapatalk

Click to expand...

Neither the IFX or Attenuator worked.

w1kne said:

Are other SDS-100 users having this issue?

Click to expand...

You're not the only one. I'm experiencing a few strange things on UHF/400MHz also. It's like the BCD436 for me felt a little on the deaf side in the same UHF range that the SDS100 now feels a little bit on the hot side. But I'm still trying to figure out more about it...

Two distinct images.
453.7000 appearing on 453.1625
453.3125 appearing on 453.8000

Have others , harder to find, in the 482-483 range.

I have seen a lot of issues with intermod / images / interference in the 460.3 part of UHF, with the Ariziona DPS. I've been listening to this system for a very long time and no top-end scanner has ever spit out the garbage I'm hearing. I posted an example in another thread. There is an issue, for me, in my situation.

My SDS-100 is due in next week at HRO Anaheim. I only paid a $35 deposit. These image problems may be a real deal breaker for me in the Los Angeles area RF jungle. I am seriously considering holding off on purchasing the SDS-100 for now. We have no real simulcast issues here in LA/Orange County area. A potentially too hot a receiver with poorer selectivity could be a real problem. Ordinarily, I would be the first to buy the SDS-100, and indeed, I am number one on the HRO Anaheim list. But these issues are concerning. Hope this is just an early bug and things will be worked out.

w1kne said:

But typically SDR's have excellent selectivity which is why this surprises me some.

Click to expand...

I think something went wrong here. Generally speaking, SDRs have never had better selectivity than standard hardware receivers.
SDR's have flexibility, frequency range and more to its advantage but receiver sensitivity and selectivity then have to take a back seat compared to the hardware designed receivers.

/Ubbe

I predicted it would have problems like this due to the low grade tuner it uses, I've not seen mention of how many bits the ADC has but if the tuner is only good enough for 8 bit resolution you'll get RF performance like a $10 dongle.

I'm not seeing similar issues, even though I live in the shadow of a cell/pager transmitter tower.