Showing posts with label tuner. Show all posts
Showing posts with label tuner. Show all posts

Saturday, September 13, 2008

My Station Equipment

I figured it was time that I talk about my station equipment. In this post, I will mainly talk about my base station equipment. In some future post, perhaps I will talk about my two HTs.


In this first photo, I have pictured my two VHF/UHF mobile radios that are currently serving duty as base stations. In the photo, you can see two mobile radio main units as well as two control heads. The main unit on the bottom is for my Icom IC-2820H and the main unit sitting on top of it is the Kenwood TM-D710A. As far as the control heads go, the 2820's head is in the foreground and has the green backlighting. The D710 control head is in back. Of course, the main reason for having the D710 is for its APRS capabilities, and my main reason for having the 2820 is for its D-Star features. These radios may never get installed in my car, but I would like to make up a box that these two radios can be mounted in and then quickly connected to the car battery and a mag mount antenna. In this photo, you can also see my Bencher iambic paddle. I barely know the Morse Code, but I have this paddle so that others can use it, particularly during Field Day.




In the photo below, you can see both of my current HF rigs, a pair of wattmeters, a pair of speakers, and a pair of radio interfaces. The larger radio is the Kenwood TS-2000X. This radio covers 160 - 6-meters, 2-meters, 70-cm, and 23-cm, but it does not cover the 60-meter channels. It has IF-DSP capabilities, satellite operating feaures, and a built-in TNC. The radio sitting on top of the Kenwood TS-2000X is the Yaesu FT-897D. The 897 has the LDG Electronics AT-897 autotuner attached. On top of the 897D are two Tigertronics SignaLink USB units. The one is the rear is connected to the Kenwood TS-2000X and has seen quite a bit of use lately. The one in the foreground is new and is connected to the 897D. I have not had a chance to tweak its settings yet. To the right of the TS-2000X, you will see a pair of speakers. The Kenwood SP-23 is sitting next to the TS-2000X, and a Vertex speaker (the MLS-100, I believe) is to the right of the Kenwood speaker. I've added both of the speakers fairly recently as I prefer their forward-firing sound better than the top-firing sound of the transceiver's speakers. On top of the Kenwood speaker, you will see the Powermaster wattmeter. That is the main display for the wattmeter. The Powermaster also has the HF coupler that samples the RF energy. It is shown in another picture. The LDG Electronics FT-Meter sits atop the Powermaster meter. As its name implies, it is connected to the FT-897D. I must say that it is nicer to read this meter than the 897's built-in one.




The next photo simply shows my sealed lead-acid battery in its battery box. Sealed lead-acid batteries are safe for use indoors as the hydrogen levels during charging are never high enough to be dangerous.




This photo shows a number of station accessories. The large black box on the floor is my Astron linear power supply. I believe that it can supply 35 amps continuous. There are two things sitting on top of it. You can see the Palstar DL2K dummy load with its backlit analog power meter. Sitting to the right of the DL2K, is a Bencher low pass filter. It's designed to not pass anything above HF frequencies, hopefully ensuring that I do not cause any unnecessary interference. I will have to remember to bypass it, if I want to operate 6-meters, though. By the way, neither of this two accessories block the ventilation on the power supply. The gold-colored box on top of the DL2K is the HF coupler for the Powermaster meter. Sitting on the floor next to the power supply are first, the Rigrunner 4008, and second, the Super PWRgate (both are products of West Mountain Radio). The green object with the small LCD display, is a meter that simultaneously measures voltage, current, DC power, and several other parameters. The sealed lead-acid battery and the Astron power supply simultaneously feed the Super PWRgate. The Astron normally runs the station, and it trickle charges the battery. If commercial power fails, the Super PWRgate allows the battery to immediately take over. The DC meter (the green thing) samples the output of the Super PWRgate immediately before it goes to the Rigrunner for DC power distribution to the other station gear.




Some of the things that I haven't pictured are my Palstar ZM-30 antenna analyzer (perhaps a future post), my HTs as mentioned before, antennas, my computer, Heil Sound Proset Plus boomset, Heil Sound Goldline GM-4 microphone (was free with the TS-2000X), and a Palstar DL1500 dummy load. I'm hoping to add the Palstar AT2K manual tuner to my station in a couple of weeks. I'll probably be talking about that, too.

73

Sunday, July 27, 2008

Antenna Tuners

I'm considering the purchase of a couple of antenna tuners to add to my station. Currently, my Kenwood TS-2000X has its own built-in tuner and I add a LDG Electronics AT-897 to my Yaesu FT-897D. I noticed recently that LDG has released a new autotuner dedicated to Kenwood transceivers. This model is the KT-100. It is similar to LDG's other autotuners in that it can tune across a wide range of impedances. This is something that the TS-2000's internal tuner cannot do. Its tuner has a fairly narrow range. The inability of the Kenwood tuner to find a successful match many times is what leads me to use the FT-897D on the HF bands. With the KT-100, however, I should be able to use the TS-2000 much more often. I do have a commercial Buddipole antenna and a Palstar ZM-30 antenna analyzer, and so I try to first make adjustments to the Buddipole (the taps on the coils and the lengths of the whips), but sometimes this is inconvenient, so I hit the tune button on the radio. Of course, I realize that by not making adjustments to the Buddipole, and letting the autotuner make the match that I am losing quite a bit of energy in the tuner.

Another tuner that I am looking at is the Palstar AT2K. This is a full legal limit manual antenna tuner. Like the LDG tuners, it can match antennas over a wide range of impedances. There are several reasons to consider a manual antenna tuner (and one that can handle higher power). First, by virtue of the tuner being manual, you can dial in the match exactly. Most autotuners, but not all (notably the Palstar AT-AUTO which uses stepper motors to drive conventional variable capacitors and variable inductors), rely on discrete capacitors and inductors and a number of relays to switch those capacitors and inductors in and out of the circuit. This will mean that the match will always be close, but not quite on. Also, some of the autotuners won't even run through a new tuning cycle if the SWR starts out less than 1.5:1 (although you can usually force them to re-tune). The second reason to consider a manual tuner is when you are only receiving. Your radio will not broadcast a carrier for any tuner if you outside of the ham bands (unless you have performed some sort of mod). When you are shortwave or utility listening, you can still use a manual tuner and tune for the strongest signal. A third reason that I see to purchase a manual tuner, but specifically the Palstar AT2K, is that the tuner is overkill for the power levels I will be using (barefoot at 100 watts or less). From some of my reading, it appears that under certain conditions, tuners can start arcing over. I suspect that arcing is more of a problem for stations running QRO, but it is probably also a problem in a small autotuner when running 100 watts because the autotuner's components are not rated for the really high voltages and currents involved. Finally, the fourth reason to consider a manual tuner, is that it doesn't care what radio it is connected to. All you have to do is put it in line between the transceiver and the antenna. With an autotuner, you more than likely need a dedicated set of cables for each radio that you are going to connect it to. If it doesn't rely on control cables, then it requires you to supply the carrier first, and then you hit the "tune" button. Of course, the main drawback to a manual tuner is that it takes more time to make the necessary adjustments.

Down the road, when I buy my Icom IC-7000, I will probably pick up a LDG AT-200Pro. I realize that LDG manufactures the AT-7000 specifically for the IC-7000, but quite frankly, the AT-200Pro has more lights and buttons. However a more appropriate reason to choose the AT-200Pro over the AT-7000 is that you can manually adjust the capacitance and inductance values (based on discrete components, though) on the AT-200Pro and improve shortwave reception.

73