Hi All, I picked this survey unit up many years ago and I was wondering if anyone recognized it. It's been running for over a day now and it has not acquired any satellites. On the top of the box it says "GPS (DSM) bypassed". That may be a clue why it's not picking up satellites, but I don't understand the reason for the bypass (if it's physical), SW can just ignore it. There is also a "SIG" SMB connector just above the 10MHZ SMB output. Maybe that is an input? Any guesses? Bob

Hi Totally a random guess ….. The input you are connected to seems to be talking about: “IF / GPS ANT IP” That may well mean that it’s one of the old style “down conversion” setups. You have a “radio” up at antenna rather than just a preamp. The input to the device is at some odd frequency like 17.123 MHz. Without the down converting antenna, they are tough to work with. Also they are old enough that things like roll over likely are an issue. Again, just a guess. Bob > On Jan 14, 2025, at 3:00 PM, rbenward--- via time-nuts <time-nuts@lists.febo.com> wrote: > > Hi All, > > I picked this survey unit up many years ago and I was wondering if anyone > recognized it. It's been running for over a day now and it has not acquired > any satellites. On the top of the box it says "GPS (DSM) bypassed". That > may be a clue why it's not picking up satellites, but I don't understand the > reason for the bypass (if it's physical), SW can just ignore it. There is > also a "SIG" SMB connector just above the 10MHZ SMB output. Maybe that is > an input? > > > > Any guesses? > > > > Bob > > > > <20250113_104318R.jpg><20250113_104329R.jpg><20250113_133735R.jpg><20250113_133753R.jpg>_______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi Bob, Sorry for the delay in replying, but something you said sent me down a rabbit hole. When you mentioned the connection, I looked at the back panel again and wondered if I connected to the wrong connector. The antenna was connected to the connector labeled "ANT I/P". I then looked at the other connector and it said "IF/GPS". But alas, when I checked the inside, the GPS antenna (my original connection) was connected to the Trimble board. There are at least two other RF cans on the other boards inside the unit. Maybe this has a radio modem inside as many survey or DGPS units have. I am not sure what the "IF" is for, usually IF inputs from mixers are for microwave bands, such as C band and K band satellite TV LNA/downconverters. So, for now, I will set this aside and call it a loss. Thanks for your feedback. Bob -----Original Message----- From: Bob Camp via time-nuts <time-nuts@lists.febo.com> Sent: Tuesday, January 14, 2025 4:24 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: Bob Camp <kb8tq@n1k.org> Subject: [time-nuts] Re: Racal survey LTD box Importance: High Hi Totally a random guess ….. The input you are connected to seems to be talking about: “IF / GPS ANT IP” That may well mean that it’s one of the old style “down conversion” setups. You have a “radio” up at antenna rather than just a preamp. The input to the device is at some odd frequency like 17.123 MHz. Without the down converting antenna, they are tough to work with. Also they are old enough that things like roll over likely are an issue. Again, just a guess. Bob > On Jan 14, 2025, at 3:00 PM, rbenward--- via time-nuts <time-nuts@lists.febo.com> wrote: > > Hi All, > > I picked this survey unit up many years ago and I was wondering if > anyone recognized it. It's been running for over a day now and it has > not acquired any satellites. On the top of the box it says "GPS (DSM) > bypassed". That may be a clue why it's not picking up satellites, but > I don't understand the reason for the bypass (if it's physical), SW > can just ignore it. There is also a "SIG" SMB connector just above > the 10MHZ SMB output. Maybe that is an input? > > > > Any guesses? > > > > Bob > > > > <20250113_104318R.jpg><20250113_104329R.jpg><20250113_133735R.jpg><202 > 50113_133753R.jpg>_______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send > an email to time-nuts-leave@lists.febo.com _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com

Bob, The TNL19032 is Trimble's Maxwell ASIC, the same IC used in the Trimble 4000SSi. It's a 6 channel receiver, usually pressed into service as 3 L1 + 3 L2 channels. If you pulled that board, you'll probably find a Motorola SoC on the other side. The presence of the ADM238LAR leads me to think it has an RS-232 serial port somewhere. I have a feeling that if you gained access to that serial port, it's probably speaking TSIP, and you could get a better idea of why it isn't picking up satellites through a tool like Visual Timing Studio or tsipchat. - Keelan On Tue, Jan 14, 2025 at 12:30 PM rbenward--- via time-nuts < time-nuts@lists.febo.com> wrote: > Hi All, > > I picked this survey unit up many years ago and I was wondering if anyone > recognized it. It's been running for over a day now and it has not > acquired > any satellites. On the top of the box it says "GPS (DSM) bypassed". That > may be a clue why it's not picking up satellites, but I don't understand > the > reason for the bypass (if it's physical), SW can just ignore it. There is > also a "SIG" SMB connector just above the 10MHZ SMB output. Maybe that is > an input? > > > > Any guesses? > > > > Bob > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com