Kendall Amateur Radio Society

KB5TX


Station Architecture for High Frequency

Think about your overall station architecture and imagine where you want to be 10 years or more from now.  Try as best you can to buy things today that will fit into your vision for tomorrow.

Radio

There are many good choices on the used and new market.  See radio choices to see what is currently offered by Yaesu and Icom.  Almost any modern 100 Watt transceiver, less than 10 years old, will have what you need for now and the future.  You will want a radio you can communicate with using a laptop or desk top PC.  Computer control is becoming a must.

Keep in mind that almost all DXpeditions will operate "split."  This means they will transmit on one frequency and listen on another, usually a few kHz up.  Best practice is to have a radio that will allow you to listen to the DX transmit while tuning through the pile-up to find the station he/she is working  Try for a radio with "dual watch" (Icom) or the Elecraft and Yaesu equivalent.  This will allow you to listen to the DX and tune through the pile-up at the same time.  Otherwise you will switch between VFO A and B or use RIT to track who and what frequency the DX is working.  This becomes your frequency to send your call sign.  More about this in DX.

Antenna or Amplifier

Where next to spend the money?  Antenna or Amplifier?  This is an age old question.  It seems to me that if you are space or deed restriction limited to a vertical or wire dipole, then I think the choice is a modest amplifier to begin; something with more punch later.  But if you can erect a tower, then the choice becomes a modest beam first and then the amplifier.  Think about this: most modest beams will give at least 3 to 5 dB of gain.  Attached to a 100 Watt transmitter, this means 200 to 300 Watts of Effective Radiated Power (ERP), minus coax loss.  All coax will have some degree of loss.  Something like RG-213 or LMR-400 will provide good performance for runs up to 200 feet or so.  Longer runs will require something with less loss.  Don't economize on coax!  The low loss stuff is worth every penny.

A vertical antenna will get you many, many DX contacts into your log.  There are many choices, elevated without radials or ground mounted with radials.  Your webmaster has used a Hy-Tower in the past with great success, and presently uses a SteppIR Big IR vertical.  Both were/are mounted on the ground over many radials.  Ground mounted, many short radials are better that a few long ones.  See the ARRL Antenna book and the Handbook.  These will tell you that 16 ground mounted radials are minimum, 32 better, 64 good enough.  More than this is certainly OK but you will be dealing with diminishing returns from your wire investment.  Make these a long as you can, up to 1/4 wave length at the lowest operating frequency.  But longer is also Okay.  Some radials at K5NOF are connected to the cattle fence around the property.  Keep in mind that Ham Radio is all about doing the best you can with what you have to work with.  Sure, there are perfect answers but one needs to wonder if the distant station can tell the difference between a vertical antenna ground mounted over a perfect radial field, compared to one over a radial field with compromises.

Electronic Logging

Amateurs are moving to electronic logging using a laptop or desk top PC.  Whatever, try to dedicate one to your station; and an old one will do.  I run Win-7 on my ham machine with multiple USB ports installed to give me multiple ports, using USB to Serial converters for my legacy equipment.  You will not need high processing speed nor a lot of RAM.  Ham radio software is not a resource hog.  Software is discussed in Lotw and Club Log and you are going to want to use it.  For now, know that you will want a package which will work easily with your radio, connect to a DX spotting network, and which you can use with LoTW and Club Log.  More about all of this here.

Station Examples

Below you will see pictures of three stations, those of N7RF, K5NOF and K9ROD.  All three commenced Amateur Radio with modest stations and antennas years ago, but both had a long term vision.

N7RF upgraded from two older Yaesu FT-950 160m-6m radios to newer models.  Doing this eliminated the separate audio interface boxes since newer radios have their own built-in audio CODECs.  He replaced sagging plywood shelves with new ones made from perforated steel doors from a 19" rack cabinet.  Dark-stained plywood end panels secure the shelf ends.  The steel shelves are joined electrically in the back with braided straps and together serve as a built-in ground bus for the station.  Radios, antenna tuner, power supply, and linear amplifier are all grounded to the shelve structure with short braided ground straps in the rear.  There is a 2.5" space below the bottom shelf to be able to store keyboards, mice, microphones, paper tablets, or code keys out of the way when not being used.  

Shelf 1 holds a Yaesu FP-1030A linear power supply, a SPDT surge-protected coax switch (to connect either radio to the HF linear and HF antennas), an LDG autotuner, and an FTM-100D FM radio on top.  To the right of this are an FTDX-3000 radio, a speaker, and an FT-911A radio.  The FT-911A operates HF or can be connected to 144/432 yagis on the tower.  Shelf 2 holds an ACOM 1000W linear amplifier topped by Daiwa HF and VHF cross-needle VSWR/power meters.  The laptop PC is an ASUS computer with solid state drive.  To the right of this is lots of additional space for "stuff". 

On the wall behind, there is a Power Pole distribution box for all the 13.8V items fed by the FP-1030A supply. To the right of that, in a small orange box, is a Pi3 computer with a DRAWS audio/GPS hat that can serve as a backup digital mode terminal for WSJT-X but is mostly used to display pskreporter propagation maps or to look up ham calls on the upper 32" monitor.  The larger 40" monitor below acts as an extended second screen for the ASUS laptop.

Not shown on a separate stand to the left is an Ameritron remote coax switch controller and a Yaesu rotator box for the 50/144/432 Yagis.  HF antennas feed into the SP8T switch at the base of the tower so there is only one HF coax line coming into the shack.  Current HF antennas include: 80m EFHW, 40m EFHW, a half wave vertical for 20/17 meters, a 5-element 6m Yagi, and a 6m omni halo.  144/432 Yagis have their own separate coax runs of low-loss 1/2" Heliax cable all the way to the input panel at the shack.

With this setup, 160m can be fired up albeit not efficiently.  The 80m EFHW has a VSWR of about 7:1 at 1.84 MHz.  This within the 10:1 tuning range of an LDG  which drops the mismatch to about 1.4:1.  Using an antenna modeling program, the predicted gain is about -15 dBi at 10-degrees elevation and 0 dBi looking straight up, not a great DX antenna.  Still, I have 21 states confirmed on 160m using FT8.  Plans are being made for a better 160m setup.

N7RF Station

K5NOF uses an Icom IC-7700 and an IC-7600, both to a PW-1 amplifier hidden in the closet at left.  The nice thing about the PW-1 is the remote control head and the ability to select two inputs and up to four antennas from the remote.  (The new PW-2 has even more remote switching capability.)  From left to right on the top shelf are two DCU-2 rotor controllers, a Palstar AT2K and a remote monitor for the IC-7700.  On the second shelf, a left monitor and right monitor presently showing DX4Win, with an IC-7600, and the PW-1 controller at center.  On the bottom shelf, the IC-7700 at center with the StepIR controller at left, and a Signal Link CODEX sound card at right.  A legacy DX-Doubler is suspended from the bottom shelf.  This allows switching audio, mike and keys from one radio to another manually or by computer.  Keying is done through the computer LPT port, as both N1MM and DX4Win have a kernel to allow this.  Antennas consist of the StepIR vertical (not shown below), a 40m Yagi, and a Log Periodic Array (LPA) for 30m to 10m, with a 268 foot Carolina Windom hung between the two towers for 80m and 160m.   

                 K5NOF 40m Yagi                           K5NOF LPA

K5NOF Station

K9ROD Station

K9ROD uses a Yaesu FTdx-1200 for HF and Yaesu FTM-350 for VHF & UHF Triple monitors to display logging program (Middle), QRZ (Left), and DX Maps (Right) all at the same time.  An external speaker with the HF rig so that the sound is not muffled by the desk top.  The desk mike is custom designed with a foot switch.  Two small lamps on both side with led bulbs light up just the desk area.

Home