Narrowbanding & Pacific Crest PDL's

It's just a wild guess,

They may be capable of narrowband but not capable of transmitting 9600 baud on narrowband. That may still put their 1999 application in violation depending on when the requirement for 4800 baud for every 6.25khz of band width was established.

James

from what I can remember being told - that maybe the radios were configured to be either 12.5kHz OR 25kHz - but not both as sold from factory? something about an internal "board"? that may have been the part that PacCrest "ran out of" earlier this year due to high demand for the $500 "re-configure/retrofit". Wish I knew more.

> Channel spacings at both 25 kHz and 12.5kHz are supported."
>

That reads in plain language to me that the PDL was touted from the beginning to support 12.5kHz channels. The fact that it doesn't seems to me to be a deliberate deception of the FCC and the consumer!

The document I am quoting is in plain view on the FCC site as part of the original filing with the FCC in 1999 for the PDL approval.

I would really like to know why Trimble/PCC isn't fixing all of our PDL's for free since they told the FCC they supported 12.5kHz 13 years ago at the time they sought approval for that product.

SHG

All of the documents filed with the FCC in 1999 can be found here (URL too long to hot link):

https://apps.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=94590&fcc_id ='KEAPDL4535'

SHG

Read "Attestation 2"

That document shows that the 25-kHz version of the PDL was approved based on the efficiency standard of 4800 bps per 6.25 kHz of channel bandwidth.

AFAIK the only protocols available in the PDL that would broadcast at 19,200 bps and meet this efficiency standard were the Pacific Crest-proprietary protocols such as "Transparent with EOT".

If your rover radio modems are Pacific Crest products then they may be capable of receiving one of the Pacific Crest protocols at 19,200 bps.

I remember a 2001 conversation with a Pacific Crest employee shortly after Trimble released the Trimmark 3, which was configurable to operate on either 12.5- or 25-kHz channel spacing. The Pacific Crest employee was surprised by that capability, claimed they did not think such a thing was possible.

GB

This is correct. Pacific Crest had a PDL radio that was 25kHz and one that was 12.5kHz, but not both. That is why, up until about a year ago you could send in your PDL/25kHz radio and Pacific Crest would modify it to the 12.5kHz version.

Brett,

Thanks for that. Do you know the reason for not just making ALL PDL's in the 12.5Khz model?

Were both models available from the beginning in 1999 and that would of been a dealer choice when ordering?

Quite honestly, I think PCC has made some poor decisions on customer support on this issue, I for one will NOT be moving forward with PCC radios because of this, just sold my PDL system AND will be using a different supplier moving forward. PCC 1996-2012, but no more.

SHG

I can understand the bitter feelings Shelby. I'm not sure it was intentional on Pac Crests part, but it sure seems like a lot of people were sticking their heads in the sand on this issue.

Shelby,

I am not certain if both versions of radio were readily available since 1999. I do know that once the 12.5kHz version was available there were different part numbers for each 12.5kHz and 25kHz radios as well as the different frequency ranges. So Pacific Crest had six different PDL HPB radios available.

As the narrowbanding deadline approached Pacific Crest was offering the modification as mentioned before, but that ended about a year ago.