Re: [time-nuts] 5V GPS antenna on 3.3V device?
Hi N0UU: Just try it. I found that many of my old GPS antennas worked on the 3.3V DAGR. http://www.prc68.com/I/DAGR.shtml#Ant Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/Brooke4Congress.html lstosk...@cox.net wrote: How's the best way to run an older 5V antenna with the new 3.3V GPS engines? Bias T? N0UU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5V GPS antenna on 3.3V device?
Yes, you need a bias T but first simply try if your antenna can workl with 3.3V too. On Tue, Apr 10, 2012 at 8:33 AM, Brooke Clarke bro...@pacific.net wrote: Hi N0UU: Just try it. I found that many of my old GPS antennas worked on the 3.3V DAGR. http://www.prc68.com/I/DAGR.**shtml#Anthttp://www.prc68.com/I/DAGR.shtml#Ant Have Fun, Brooke Clarke http://www.PRC68.com http://www.**end2partygovernment.com/**Brooke4Congress.htmlhttp://www.end2partygovernment.com/Brooke4Congress.html lstosk...@cox.net wrote: How's the best way to run an older 5V antenna with the new 3.3V GPS engines? Bias T? N0UU __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5V GPS antenna on 3.3V device?
Personally I would just try it. It seems highly unlikely that it wouldn't work. There might be some degradation of gain, but certainly worth a try. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of lstosk...@cox.net Sent: 10 April 2012 04:29 To: time-nuts@febo.com Subject: [time-nuts] 5V GPS antenna on 3.3V device? How's the best way to run an older 5V antenna with the new 3.3V GPS engines? Bias T? N0UU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5V GPS antenna on 3.3V device?
Bias T yes, but also a light load on the receiver antenna jack to let the receiver know there is an external antenna and thus switch from the internal patch antenna to the external antenna jack. I determined the required load resistance by using a resistance box coupled to the antenna and starting at 50K, lowering the resistance until the receiver switched - at which time all of the signals disappeared. DO NOT GO BELOW ABOUT 200 OHMS. John WA4WDL -- From: David McGaw n1...@alum.dartmouth.org Sent: Tuesday, April 10, 2012 12:29 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5V GPS antenna on 3.3V device? Yes, a bias T is needed. The same is true for some hand-helds like the Garmin GPS-60CSx which also only put out 3V. 5V antennas like the Synergy VIC-100 have very low gain at 3V. 73, David N1HAC On 4/9/12 11:29 PM, lstosk...@cox.net wrote: How's the best way to run an older 5V antenna with the new 3.3V GPS engines? Bias T? N0UU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5V GPS antenna on 3.3V device?
On Tue, 10 Apr 2012 05:29:20 +0200, lstosk...@cox.net wrote: How's the best way to run an older 5V antenna with the new 3.3V GPS engines? Bias T? Assuming you want to open up and modify your GPS: In many GPS devices you'll find the biasing circuit easily just next to the antenna connector, built with discrete components. Sometimes you'll have to look in the datasheet of the GPS module, there will be a (often well accessible) pin to feed the bias voltage. Typical circuit: Antenna o--+-||---(GPS-Input-Amp) | | +---/\/\/\(Vcc) RF I-limit ChokeResistor Just lift up the I-limit resistor and feed in the suitable bias voltage to the RF choke. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Lucent 40 dB Antenna
My Lucent antenna arrived today. I scrounged some adapters and connected it to my Thunderbolt. Two birds were visible with AMU 4 when I held the antenna. My Droid 3 could not see any birds through the wet roof. The unit has some dings and scrapes but no visible corrosion. I am tempted to take it apart but don't wish to break a unit which seems to be working well. Has anyone compared this antenna with the mushroom that came from China with the used Thunderbolts??? -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent 40 dB Antenna
Chuck wrote: My Lucent antenna arrived today. Has anyone compared this antenna with the mushroom that came from China with the used Thunderbolts??? I have five GPS antennas -- a Garmin mag-mount puck designed for vehicular use, a Garmin marine mushroom, a Lucent timing antenna like yours, a Trimble Bullet 3 (the antenna specified by Trimble for use with the Tbolt), and an Aerotenna choke-ring survey antenna. Deployed in the same location, they all give very similar signal reports from the Tbolt and track the same number of satellites (remember, the Tbolt reports the carrier/noise ratio, not raw signal strength, and c/n is closely correlated with the signal environment at the antenna location unless an antenna has way too little gain or a very noisy preamp). This suggests that they all have sufficient gain and low enough noise to work properly with a Tbolt. The one difference I observe is that the choke-ring antenna shows consistently less variability in its surveyed position, and lower deviation of both the 10 MHz and pps, than all of the others. I assume that this is due to reduced multipath, but I have no way to verify it. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucent 40 dB Antenna
On Tue, Apr 10, 2012 at 10:02 PM, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: ... Deployed in the same location, they all give very similar signal reports from the Tbolt and track the same number of satellites (remember, the Tbolt reports the carrier/noise ratio, not raw signal strength, and c/n is closely correlated with the signal environment at the antenna location unless an antenna has way too little gain or a very noisy preamp). This suggests that they all have sufficient gain and low enough noise to work properly with a Tbolt. That is what I think too. That location matters so much more than any other factor. Even a few feet difference matters. I see a difference between laying the antenna on the roof and placing it three feet above the roof on a pole. Where are you placing your antenna? I'm curious because you say the choke ring helps. Is it close to the ground, near a building? What might be the cause of the muiltipath that the choke ring is helping with Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
