N5NA

I recently purchased a Globalsat ET-102 GPS receiver board off of eBay. It was a good deal at $3 for the receiver and $3 for the antenna. With shipping it came out to $10.80. When the package arrived there were two boards and two antennas. Guess he was just trying to get rid of them because he later offered a board and antenna for $3 total so I bought another!

A Google search turned up a product sheet on the ET-102. It's a 12 channel SiRF receiver, whatever that means. The serial output is at TTL levels so it can't be connected directly to a computer's RS-232 port. I was planning to use it with a Byonics TinyTrak3 which will accept TTL levels. However, I wanted to test the receiver with my computer so I ordered an RS-232 to TTL level converter from NKC Electronics.

When the GPS boards arrived I connected one to my computer through the level converter. I like to use VisualGPS to check the GPS NMEA output. The ET-102 was only sending out gibberish. I reversed the TXD and RXD connections between the GPS and the level converter and started getting NMEA sentences on the monitor. It works! However, the GPS was only sending out the $GPRMC sentence. While the TinyTrak3 will accept $GPRMC sentences VisualGPS will not display any information with only that sentence. I wanted $GPGGA, $GPGSV, and $GPGSA sentences to get a good test on the GPS.

More Google searching turned up a product sheet for a Globalsat ET-212 GPS board. That datasheet had some NMEA input commands as well as the output sentences. So, I decided to try those commands to turn on the other NMEA sentences I wanted.

I have previous experience sending NMEA sentences to a Furuno GN-80 GPS. The only tricky part is you have to send a checksum at the end of each command. In working with the GN-80 I found a website that had a script to calculate the checksum for NMEA sentences. How convenient! The website was public domain so I copied it, modified it slightly and set it up at nmeachecksum.eqth.net so I wouldn't lose the site just in case it went away sometime.

With the input commands and the checksum determined I just needed a terminal program to send the data to the GPS. I found a program called Realterm that worked great for this purpose.

So to turn on the $GPGGA sentences I sent "$PSRF103,00,00,01,01*25" to the unit and it immediately starting sending the $GPGGA sentences as well as the $GPRMC sentences. So, the ET-212 commands work! I sent the appropriate commands for the other sentences and I was in business.

The GPS works great! I was able to receive 7 satellites with the antenna in the window. When I took it outside I was receiving 9 of the 10 satellites in view. Next was to try it with the TinyTrak3.

To use TTL levels you have to check a box in the TinyTrak configuration software. I set that up in the configuration but when I connected the ET-102 the TinyTrak didn't show it was receiving GPS data. I thought I was just going to have to use a level converter but I read the TinyTrak documentation (helps sometimes!) and found the TinyTrak checks the GPS for TTL data when it is first powered up. I had not turned the TinyTrak off when I connected the GPS but when I did that the TinyTrak started receiving GPS data!

So, look for N5NA-9 on findu.com!

Last week I finished up installing my FT-7800R dual band transceiver in my Smart. I installed the radio under the passenger seat held in place with "Industrial Strength" velcro. (Not K0BG approved!) Velcro sticks to the carpet in the Smart great! That location made for an easy route to the battery for power and to the antenna mounted on the rear spoiler.

I had the radio in the car for a couple of weeks before I settled on a mount for the control head. I finally decided on an LM300 floor mount from Lido Mounts. After ordering the LM300 I found a thread on eHam with lots of complaints about Lido Mounts. Fortunately I received the mount one week after ordering. The same type of mount is also available from mountguys.com.

For an antenna I purchased a Comet CP-5NMO lip mount and a Comet SBB-5NMO antenna. The SBB-5 is marketed as a "ground independent" antenna. I installed the mount on the rear spoiler, straddling one of the screws that holds the spoiler on. I had to reconfigure the mount slightly so the large wing nut doesn't hit the roof when the rear window is opened. The antenna works great! I did tilt it over at about a 45 degree angle so it wouldn't hit the garage door. I haven't had ANY RFI problems running the rig on high power.

Below are some pictures of my installation.

My long awaited Smart arrived in San Antonio on March 21. My wife and I made a quick one day trip to S.A. on Wednesday, March 25. The drive down only took 4-1/2 hours. You can make pretty good time when you can drive 80 MPH on I-10!

The salesman was waiting on us when we arrived and gave us both a short driving lesson to learn how to operate the manual automatic transmission. The purchase went pretty smooth since I had told the salesman ahead of time I didn't want the "anti-theft window etching" they had included in the TT&L total for only $97.50. I don't know why dealerships try to stick you with stuff like this. Turns out they did the glass etching anyway so I guess that was a freebie. I tried to get some free floor mats thrown in but couldn't talk them into that.

Next stop was the finance man. He did a really poor job trying to sell us an extended warranty. Maybe that's why he's the finance man and not a car salesman!

After giving the finance man our check we were ready to head back to Midland. We made a stop at the parts department to pick up some floor mats on the way out since I couldn't get them for free. Gotta have floor mats!

The little car is a blast to drive! On the way home I got it up to 80 MPH a couple of times but mostly drove between 65 and 70. It seems to be pretty wind sensitive. We drove into some heavy rain, wind, and hail near Junction. Fortunately the hail was small and the storm was short. It was clear sailing on home from there. We stopped in Ozona for gas since I was down to 1/2 tank at that point. It took 4.8 gallons to fill up which worked out to about 41 MPG. Hopefully I'll continue to see mileage in that range!

Next trick is to figure out how to mount an antenna!

I finally received word today from Smart Car in San Antonio that my car should be arriving around March 23. Juan at Smart Car said he expected it would actually be between March 15 and March 20. That makes it right at one year since I sent in my reservation.

Hope I like it!

This past weekend I participated in the NM QSO Party as an in-state mobile. K5AKS (my wife) and I drove over to NM on Saturday morning. Since the QSO party didn't start until 10:00 a.m. MST it was easy to get into NM from TX without having to head out too early.

We arrived in Hobbs about 30 minutes before the start of the QSO party. I rigged up my laptop, keyer, GPS, etc to get ready. The first problem I had was getting the GPS going. I use a Garmin GPS 18 USB. The GPS 18 USB uses a propriety format so to be able to use it with my logging program, CQ/X by NO5W, I have to use a Garmin program called Spanner. However, Spanner did not seem to be passing the data to the virtual com port I had set up. So, as a fallback I connected the GPS I normally use for APRS. It seemed to be working so I was in business.

I was a few minutes late starting the contest by the time I got the GPS going. Then the logging program froze. After about an hour battling that problem I finally figured out I had an RF problem causing the logging program to lock up. I had added a second antenna to my truck. In addition to my High Sierra HS-1500 screwdriver type antenna I had installed my Texas Bugcatcher antenna to give me the ability to quickly switch bands. In hindsight, the serial cable running to the GPS was picking up some RF from the bugcatcher coax. I quit using the bugcatcher and worked the contest with the screwdriver antenna and didn't have any more problems.

In total we drove through ten New Mexico counties. The route covered about 630 miles from Midland to Santa Fe. I finished with 259 QSO's and 47 mulitipliers. Of the 47 multipliers I only worked four NM counties.

The 160m antenna described in my previous entry works amazingly well. I operated in the CQWW 160m Contest this weekend and was able to Work All States. In addition, I worked a number of countries including Chile, Denmark, Scotland, France, Japan, Luxembourg, Sweden, and Hungary. In total I made 343 QSO's on 160m this weekend which more than doubles my lifetime 160m QSO total of 230 QSO's!

Doing some research I've concluded this antenna is basically a half-sloper. Or maybe a low half-dipole since it's not sloping. WD8DSB made an interesting post to the Top Band Reflector in 2001 which describes some measurements he took of the feedpoint impedance. He concluded if the half-sloper is not mounted very high from the ground the feedpoint impedance would provide a reasonable match to 50 ohm feedline. I had considered raising the feedpoint up the tower but there may be little to gain and it could affect the feedpoint impedance. K6SE(SK) made a followup post stating polarization is predominately vertical with the azimuth skewed in the direction of the wire.

Bottom line is IT WORKS!

Yesterday I put up a 160m antenna. The only other time I've been on 160m was with a 160m coil on a Butternut HF-6V vertical.

The antenna I installed was copied from W5AJ who got the idea from W5UN. It's really simple and cheap. I attached the braid of a piece of coax to my MA-550 tubular crankup and the center to a piece of #14 insulated wire about 125' long. I started with 138' of wire but had to keep cutting it off to get the resonate frequency into the 160m band.

The braid is attached to the tower about 8' off the ground and the wire runs west from the tower to a pole such that the end is about 10' off the ground. The center sags to about 6' off the ground. The tower is cranked up to about 50'.

I'm amazed the SWR is 2:1 or below from 1.817 MHz - 1.991 MHz. I suspect with such a broad bandwidth on 160m the antenna is lossy and inefficient. However, I did talk to W5AJ across town last night so it is better than a dummy load!

I'm planning to lengthen it just a bit to lower the SWR on the low end of the band. I'll give it a good test in the CQWW 160m Contest this weekend. If it really works I'll weather proof the connections.

I placed my reservation for a Smart car in March, 2008. In September I received the email to configure my Smart.

After configuring the Smart delivery date estimator (DDE) showed delivery between December, 2008, and February, 2009. Then after a couple of weeks it showed November, 2008, to January, 2009. Then the delivery date disappeared for a couple of weeks. Then it came back with a specific day interval. I can't remember what it said at that time but today it is showing February 17 to May 18, 2009. Every day it seems to move out another couple of days. It will look like the one in the photo, if I ever get it!

Of course, if I ever do get it the next challenge will be figuring out how to mount an antenna. The body is composed of plastic panels. The silver part in the photo is a Tridion safety cell made of steel. I really don't want to go drilling into that. I have seen some hams use some type of glass mounted VHF/UHF antenna so I'll have to check into that.

The RTTY roundup was fun, as usual. We had four participants from Midland...myself, W5AJ, K5NAA, and WA5PFJ.

I finished with 667 QSO's and 72 multipliers for a claimed score of 48,024 points. The bulk of those were on 20m but I had 119 on 15m and even one QSO on 10m! I managed to work all the states so that should give me a jump start on the Triple Play award. Hopefully there will be lots of folks uploading their logs to the LOTW. I've already uploaded mine and as of 8:00 pm I already have 29 confirmations toward the Triple Play award.

The next operating event I'll be participating in is the NM QSO Party.

The ARRL RTTY Roundup is this weekend.The NCCC sponsored a practice run tonight from 0230Z - 0300Z.  I got in and made a few contacts on 40m to check if N1MM is set up correctly.  Everything looks good.


Tomorrow I will put up a dipole for 80m.  Tonight most of the activity was on 80m and my Carolina Windom just doesn't work on 80m without a tuner. There will be another practice run tomorrow night so I'll check out the 80m dipole then.


Hopefully I'll get a good start on the ARRL's Triple Play award!

Welcome to my new home page!  I'm learning and trying out a blog script called Serendipity.  So far, I've found it easy to install and use.  Nothing fancy here but does the simple job I need.