SDS100/SDS200: SDS 200 slow GPS

[Jakeguy24]

I travel with both an SDS100 and SDS200, both using the uniden bc-sgps kit. The sds100 always finds the gps signal within a minute or 2. The sds 200 doesnt. Sometimes it wont find the signal after 5 minutes, ill have to turn it off and back on. Ill sometimes have to repeat that process a couple times before it finds a signal. both gps pucks are within 12 inches of each other on the dash. Ive tried swapping pucks, and tried swapping the locations of the puck, with no difference made.

Anyone else experience this, or have any idea how to fix this? Is there a better aftermarket gps unit i could be using for the sds 200?

 

[dave3825]

What is the baud rate set to on the 200?

 

[Jakeguy24]

9600

 

[dave3825]

Not sure then. I just checked my 200 and its set for 4800, and while that's the default setting on the 200, it worked 2 months ago when I used gps on it.

 

[nessnet]

My experience: (both radios and their GPS next to each other)

The SDS100 with it's puck (basically a BR-355S4) acquires GPS lock fairly quickly.
But, an SDS200, with the CB-GPSK takes considerably longer.

I always thought that the CB-GPSK just had lousy sensitivity.
Your situation makes me thing maybe it's the radio also.

Anyway, I have experienced an SDS200 taking way longer to acquire lock myself.
In your case if the GPS module is basically the same, this points to the radio.
Which, if this is the case, there isn't much that could be done.

 

[kruser]

I have a 200 and a 100 with identical favorite lists and profiles minus the opening message which is the only difference in programming between the two.
They both contain the same favorite list which totals 96 favorites.
The SDS100 boots up and starts scanning 16 seconds faster than the SDS200 does.
I always figured there's maybe a different processor in the two or perhaps the 100 is running at a faster clock speed.
Oh, the SD cards are also identical 16GB Sandisk Industrial micro sdhc cards bought together. This tells me there is a difference between the two models. The USB sections could be different between to two models in the boot time case but something tells me something else is responsible for this slower boot time on the SDS200.
Perhaps the slower GPS detection is somehow related to the noticeably slower boot time between the two models.
I recall someone else saying something about their SDS100 also being faster to boot than their 200 but I didn't follow that thread.

I've never measured GPS detection times!

 

[consys]

The internal case volume of the SDS100 is smaller. It fills up with signal faster than its larger cousin.

I'll see myself out now...

 

[JoeBearcat]

My experience: (both radios and their GPS next to each other)

Twp GPS pucks in close proximity will sometimes interfere with each other. Keep them at least a foot apart.

 

[nessnet]

Twp GPS pucks in close proximity will sometimes interfere with each other. Keep them at least a foot apart.

.... > 1 foot apart.
Probably better said... both have the exact same view of the sky

 

[donc13]

I don't have an sds100 but do have an sds200. I timed the startup from power on to scanning. 18.27 seconds. I load 1 favorite list only and do have gps. I scan 5 counties but 95% all the traffic from those counties is on out state DTRS system (5 nearby towers) and BLM, FOREST and a few other federal agencies. All with location control on via gps. Since the radio retains the location where it last was, it does not have to wait until it gets a gps signal.

Not knowing what you are loading on your radios, I can't imagine an sds100 booting up 16 seconds faster.

 

[kruser]

I don't have an sds100 but do have an sds200. I timed the startup from power on to scanning. 18.27 seconds. I load 1 favorite list only and do have gps. I scan 5 counties but 95% all the traffic from those counties is on out state DTRS system (5 nearby towers) and BLM, FOREST and a few other federal agencies. All with location control on via gps. Since the radio retains the location where it last was, it does not have to wait until it gets a gps signal.

Not knowing what you are loading on your radios, I can't imagine an sds100 booting up 16 seconds faster.

My SDS200 takes 44.2 seconds from power on until scan.
My SDS100 takes 30.0 seconds from power on until scan.

I took the SD card from the 200 and put it into the 100 for this test. No GPS enabled or hooked up on either model.
So both models were loading the exact same data from the same SD card. It consists of 96 favorite lists but only one is enabled. Disable the enabled FL to get a Nothing to Scan message results in the same timing as when a favorite is enabled.

The SDS100 has either a faster data bus for reading the SD card or it has a faster processor. I've never looked up specs to see if the two models use the same exact processor or not but the 100 is noticeably faster to boot to a ready state. This was also noted by others after both models were available for purchase as well.
Ive never tried to test scan rates between the two models but if that is the same, I think it indicates the faster boot on the 100 is due to a faster data bus for the SD card.

Uniden's SD card models seem to use USB 2.0 speeds while the GRE designs seem to transfer using slower USB 1.1 speeds. That's from tests I did with a GRE PSR800 and TRX2 years ago now. This was the USB speeds between the scanners and the host computer and not related to the boot to ready time of the respective models tested.

Either way, the boot time is not a big deal. I have plenty of things to get ready while the radios are booting up!
They all scan at a rate that seems plenty fast for my needs.

 

[Ubbe]

There was one bug in the SDS100 firmware, and then probably also in SDS200, that made the scanrate be 45ch/s for a couple of years. Then in some recent firmware upgrade, maybe 6-8 months ago, they fixed that bug and now I measure 78ch/s in a SDS100E.

I'm pretty sure that they use the exact same processor and DSP in both SDS scanner models, but the SDS200 have some extra functions in its firmware like the network port handling that could need some extra time to setup and detect a router and look for external commands and so on. The more hardware to manage the longer it will take for the firmware to check and validate that hardware.

If having both models you can time it takes to load all favorite lists from the state where all are unselected. That would show the SD card interface speed.

/Ubbe

 

[dave3825]

I timed the startup from power on to scanning. 18.27 seconds. I load 1 favorite list only and do have gps. I scan 5 counties but 95% all the traffic from those counties is on out state DTRS system (5 nearby towers) and BLM, FOREST and a few other federal agencies.

My SDS200 takes 44.2 seconds from power on until scan.

96 favorite lists but only one is enabled.

Disable the enabled FL to get a Nothing to Scan message results in the same timing as when a favorite is enabled.

Wow, and I actually thought mine was slow.


My 200, set to load 4 fav lists, takes 20 seconds from power on to start scanning. 2434 total freqs and 1018 talkgroups.



With no lists enabled to scan, Power on to Nothing to scan is just under 8 seconds.

Disable the enabled FL to get a Nothing to Scan message results in the same timing as when a favorite is enabled.

Something does not seem right there.