K3LFO/W3DIO Rover Site

We unfortunately had to cancel our trip to Dayton. Probably a good thing. Will have saved a ton of money in gas with the RV @ 6 MPG and even more money on purchases 😉

Today, I worked on a few things.  First and foremost, I opened up the 222 transverter and discovered that the only way to get down to 2 watts out of the transverter was to drop the IF power down to 5 watts (lowest the TS-2000 will go on 28 Mhz.).  Once i had that set and tested it, the overdrive/swr fault protection did not kick in.  It looks like that cured our problems we were experiencing on 222.  Before, with our typical 10 watts IF drive, we were getting over 5 watts out which was overdriving the Mirage amp.  This is probably because when I set the drive level originally, I was running at 13.8v and our equipment is all set at 14.2v.

With that complete, I moved on to the next task in the garage.  I cut some aluminum angle-bar to make two little 90 degree brackets.  I’m using these on the 2 meter amp so that I can attach the large size 0 wire and connectors horizontally as there is not enough room between the shelves to do it vertically as you normally would.  Did a really good job with that.. I didn’t take a picture though. I’ll have to do that.  Once I test this, I may just make some more of these for the other TE Systems amps.

Dad(Jim) has been working on a PTT relay box.  We recently discovered (by reading the manual) that the ptt lines out of the TS-2000x are rated at 20ma  max and that the down east microwave transverter ptt relays are rated at 25ma.  We have been very lucky we have not blown the IC that controls all those PTT lines.  So we will be installing a PTT interface that will isolate the ptt lines and allow us to connect them to devices that can draw up to 3amps.  We dont have anything that draws that much current but it’s always best to over engineer these things.  He also working on building a relay box that will be used in conjunction with an Ameritron remote coax switch to switch between the various microwave IF’s and PTT lines.  This will make it really cool and easy to switch between bands on 2304 through 10G.  The nice thing will be that we will eventually have this wired up so the 5th posiion on switch is straight through 2 meters going to a 160 watt amp which will connect to the 2 meter square loop at the front of the RV.  Our goal is to have the second ts2000x handle all bands from 903 and above for microwaves and be secondary on 6 through 432.  We will eventually add a second 222 transverter to the RV for this purposes.

We spent some time today figuring out how we were going to integrate 3.4ghz into the RV.  We decided a few things:

1. We are going to purchase a DEM 2304 transverter and a 2.3 ghz 60 watt board from pyrojoseph so we can create a much smaller package than we have now for 2304.  Once we have this new package put together we will take the old one and remount it in a nice chasis and set it up for use at either my house or as standby equipment for that band.  You can never have enough redundancy.
2. We are going to stack the 2.3 and 3.4 ghz transverters and place the amps for both bands in such a way so they both fit on the same shelf with the transverters.

Our plans for June are just to get on the air with 1 watt for 3.4ghz.   The amp will be integrated hopefully before September.

Add a little line resistance, about 54 amps of current and wah-lah you get just over 1 volt drop. In our rover we are using a DC Power 75-amp powerpole distribution block. Being rated to handle up to 75 amps of current it is connected to the power supply with a #6 wire. 4/10th of a volt drop is just from that wire and the junction across the fuses. The rest is the number 8 wire going the rest of the way to the amplifier which has about 5 feet of wire. Unfortunately a large portion of this loss appears to be coming from the crimp-on 75amp powerpole connectors. The solution? Unfortunately our nifty little power distribution block needs to be removed from the picture and we are going to have to use larger wire directly to each of the high power amps.

Why is this an issue? We found that our brand new TE Systems 0552g 6 meter 400 watt amplifier puts out about 270 watts when driven to maximum input power of 25 watts. This is caused by the losses we incur from the line resistance. We verified that the power supply itself is still regulating at 14.2v. Therefore the only solution is to increase the wire size and only used soldered connections as some loss may be caused by the crimp on powerpole connections. We also found our TE Systems 1452G 2 meter 400 watt amplifier puts out about 280 watts when drive with its maximum input power of 25 watts.

So two weeks ago dad soldered up, using the propane torch, some rather hefty terminals on the end of some rather large (size 00) welding cable that Brian Skutt(ND3F) donated for the cause. Since the wire and terminal lugs on it are quite large, I used some 1″ shrink wrap around it to help prevent accidental shorts. I found that the hairdryer I was using worked well to get most of the job done and shrunk the heat shrink evenly. I followed up by waving the propane torch across it which smoothed out any bumps or bubbles and make it look really nice and a tight fit around the wire. I then went back to the RV to test it out. Unfortunately the terminals (1/4″x20) on the power supply aren’t long enough to just add this connector on so at Dad’s suggestion I replaced the brass terminals that were 1 1/4″ long with 1 1/2″ long terminal bolts. We then wired it up to the 2 meter amp. I hooked the bird watt meter and bird dummy load in line on the output and gave it a try with just 5 watts input. I was shocked to see about 290 watts output. This is more than we’ve ever seen with the max 25 watts input. At 10 watts input it puts out over 300 watts. At 18 watts the amp is putting out 400 watts and at 25 watts it now puts out about 420 watts. WOW. What a difference. When we measured the voltage at the amp DC power terminals while transmitting we read 14.06v. WOW.. The only way to improve that would be to run a sense line from the power supply out to the amplifier but I think 14.06v is perfect. Really impressed. In fact this is the very first time we have ever seen the rated power output of this amp. When I bought this amp they rated it at 400 watts and then shortly afterwards changed their ads to say 375. I dont know if the model I have is only supposed to do 375 or not but it seems to work. We tend to be a little conservative on amp power anyhow so we will probably run it anywhere from 10-18 watts input.

Now I need to replace a cross-threaded ground terminal on the new 6 meter amp and then install it on it’s shelf rails. The idea is we will run the #00 wire to the two meter amp in the RF closet and then from there run a #4 wire the few feet from there to the 6 meter amp. We also need to eventually replace the 6 meter coax but more importantly we need to replace the 222 coax as it is just too short and the connector has intermittent connections with it’s shield.  We also are still waiting on the 3456 transverter on order from Down East Microwave and have some antenna/mast work to do before the June contest.

Thanks Brian(ND3F/N3IQ) for all your help and your donations to the rover cause.

My QST finally arrived with the September results and a couple of surprises.

Despite what I considered a meager score submitted at just over 76K the K3LFO Rover standings were:

5th place overall Nationally in the Rover Category with a “Top 10” listing in QST!

1st place Rover in the Atlantic Division!

1st place Rover in the North East Region!

Another surprise was a reduction in submitted score to just over 70K. Where did 6000 points go? It seems that besides the usual mistakes of entering a call or two incorrectly, 8 contacts did not show up on the other stations log! Now a couple of those may have been hitting the wrong band switch in the logging program. One or two may have been mistaken compleations. But, I noticed some that when you look at our log they were part of a sequential run up the bands with one station. Now when you run the bands with a stations you don’t just jump over 222 and go to 432 without a completion. My conclusion is that about half of these were logging mistakes from the other station for which we were penalized. We’ll try to be more accurate next time!

This was our first outing with 2304 abord and it performed quite well.  Add 2304 at 50w, our new 150w amp for 1296, and a beautiful tropo opening from FM08 through New England and we really kept busy!

Murphy strikes less and less each time we go out.  The system has become very reliable with exception to a couple of old RF cables that need new connectors and normal ware and tear on things.  The 1296 looper took a tree strike a while back and needs to be re-tuned but still did a great job.

Even though it was not quite what you call a best effort, we are really proud of the results. We do not make advanced scheds, we don’t grid circle, we don’t pack rove, we haven’t run digital modes (yet), we try to work anyone we hear, and we don’t look for ways to manipulate the rules. We just go out in the RV and have a really fun weekend!

73, and see you in June,

Jim K3LFO