K3LFO/W3DIO Rover Site

2008 Spring Sprints

The Preparation:

We’ve been trying to get done various projects in the RV. Unfortunately timing of things and other parts of life have not been helping lately. The one thing that is really positive that the antenna mast was left up all winter long on the rover and it has sustained 60mph winds. It’s survived! That being said we still have a few critical bolts on the mast that we want to replace before the June contest to ensure our continued success. We are trying to put in a partial battery backup system for the rear closet equipment. Currently all of the equipment in the rear closet is attached to the Astron RS-70m. Our plans are to get another Astron SS-30 (30amp switching supply) to power all of our 30amp and less equipment and then attach that to a new West Mountain PwrGate (the non battery charging one). This will give us instant fail over for all 12-volt equipment (transverters and 220 amp). Then the current plan is to attach the higher current equipment that is still on the RS-70m to a high current manual switch and be able to switch between battery and the RS-70m.

As we are making these improvements and changes, the sprints give us a good opportunity to test these systems out. We’ve had a battery backup for the front two radios for a while now. We are using 2 30 amp/hour gelcells charged by a West Mountain Super PwrGate which also provides instant failover to battery backup. During the sprints I have been running only off of battery to test them out and everything seems to work out great.

In the end it really just comes down to this: “Turn on power. GO GO GO!”

The Equipment:

The Configuration:

144 Mhz (04/08/2008):

It appeared that conditions were pretty decent and there was definitely a lot of participation. We operated from the rover vehicle at my Dad’s QTH (K3LFO). Operated until about 9:30pm. Had a blast. Ended up with 35 qso’s and 12 grids. Furthest north was FN31 and furthest South was FM06. A lot of CW activity which was nice.

222 Mhz (04/16/2008):

Again conditions during this sprint were pretty good. Although there was significant less activity than the previous week on 2 meters, we still did pretty well considering where the rover is parked. We do not bother with going on a rove during a sprint as the time frame is just too short and it’s a work night. We operated from 7pm until about 9pm. We did 15 QSO’s and 10 grids. K1TEO was the furtherest North and nice and strong down our way as usual. The farthest south was KG4HOT in FM07. Although we heard several people working stations from 8 land, we didn’t hear them down our way. It’s kinda rare that we do due to hills to the west.

We were experiencing problems with the SWR alarm tripping on the Mirage C211 amp. In the process of trying to figure it out we found two problems. The first problem is we had significant reflected power on the coax. We have been meaning to replace this for a long while and hope to do so before the June contest. This coax has been giving us grief as it is just barely long enough to make it to the amplifier where it sits and I believe the coax shielding pulled away from the connector slightly. The second thing I found is when I measured the RF coming out of the transverter it was putting out about 3 watts. The amplifier is a 2 watt amplifier. So the amplifier was putting out it’s max 110 watts out as it should but we are driving it a little too hard. This probably happened because when I adjusted the transverter back to 2 watts after field day a year or so ago, I was on a batter or a power supply with 13.8v. Our RS-70m runs at 14.2v as some of the equipment requires that and it doesn’t hurt the others. This was just an oversight on our part so we will just need to pull it out of the rack and adjust it. No a big problem to handle. We like it when they are simple 😉 For our transverters, since they have the 10 watt attenuator from Down East Microwave in them, we typically set them for max power out (for our application) with 10 watts in. This means with 10 watts IF drive it will put out 2 watts to drive the amp to max. When we did our check we were running 5 watts IF drive and getting 3 watts out. Then we typically back the IF rig off by a few watts so as to not run our equipment at max power all the time and risk overheating or damage.

432 Mhz (04/23/2008):

We got a little bit of a late start due to dinner and Dave was in the middle of repairing our 6m amp. After the minor repairs were complete of course we needed to test it out. With max power in we are only seeing about 290-300 watts. This was with using our new size 00 DC cable. Under full power input to the amp, we still read about 14.06v which is perfect for what we need. So perhaps while we are out at Dayton we can tune the amp one evening.

We operated from about 7:30 until almost 10pm. Unfortunately with obstructions of nearby trees and operating from not the best of locations for 432, we really didn’t do that well. In fact band conditions didn’t seem to be that great. We only did 13 Q’s and 8 grids. Most of them were on CW. We worked down south into FM06 but didn’t work anyone to the North or NorthEast past FN21.

After we got bored with calling cq and getting no response and not finding anyone else to work around the band, we decided to check the voltage on the 432 amp. We recently added a second set of power cables, to the 432 amp, to make up for some of the voltage drop we were seeing through the DC power 75-amp power pole distribution block and #8 wire. Under keydown with full drive power the voltage was just about 13.6v. This is great because .6v loss is exactly what we saw at the distribution block after the #6 cable going to the power supply. We decided for now this is adequate and we will eventually replace the power cable with something a little more heftier. Unfortunately because of the sheer size of the Astron RS-70m we could not fit it in the closet so some of the power runs have about 10 feet or better to travel.

903 Mhz + (05/03/2008):

Didn’t get on the air for this sprint.

50 Mhz (05/10/2008):

Got on the air for the last spring sprint of the season. Conditions were beyond miserable. Worked K1TEO up in the Northeast but he definitely wasn’t as loud as he usually is heard. Had a difficult time even working WA2FGK which in all the other sprints was really easy. Working a bunch of people to the south but the content seemed like it was over by 8pm. We took turns operating and banged out a few more contacts but by 9:50 it just seemed like the band was dead except for K3CB on CW, K1RZ and W3ZZ. Well better luck in the fall perhaps. Now looking forward to Dayton next week and then the June contest.

The Results:

Here are the results for each band during the Sprint Sprints: