VHF Contests

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From Flagpole Knob, looking East towards Harrisonburg

Here are a few notes for the W4IY VHF contest station.


Flagpole Knob, VA. Map to the site. Google Earth Image - Here

Lat           Long
38 30.591N    79 11.052W
38.5098N     -79.1842W
38 30 35.44N  79 11 3.13W

Declination 10deg W (-10deg)

Station Diagrams

Station diagrams and notes for each station are listed below. Use the drawings marked 'current.' The older drawings are kept around for prosperity and to help us remember what we tried in the past.

Single Station

In 2019, we decided to drop to a single station. We ran the June contest from Blue Knob, PA. We stayed in a run down ski lodge. The station used the club's white trailer and KM4KMU's jeep with antennas. I helped John tune the antennas before hand. Operation went well, but we lost the 2M W6PQL Amp 15 minutes into the contest! We replicated the station in Sept 2019.

[PDF] - June/September 2019 Single station diagram.

432/2M and 6M/22 Combined Operating Positions

We started running out of operators. So in Sept 2011, we dropped down to two operating position. Each position has two radios and N1MM is set up in a SO2R configuration. However, both AMPs at each position are keyed each TX cycle to protect the receiver front ends. The SO2R configuration allows the operators to switch radios and log entry windows with a single key. We also removed the 2M and 432 preamps because the antennas are mounted next to the Woodbridge Wireless communications trailer. The trailer was located close to the old 2M tower location and the 6M/222 tower was located where the green army tent used to go. (top of the hill) [We discovered long ago, this is the best location for the antennas to reduce interference between stations.]

432/2M and 6M/222 Diagram June 2014 - Flex500A and Elecraft K3 - [PDF] - fixed audio issue by using the Microham's isolation transformers.

432/2M and 6M/222 Diagram June 2013 - Used the Flex5000A V/U and Elecraft K3 (6 and 222)

432/2M and 6M/222 Diagram June 2012 and Sept 2012- PDF - VHF Combo Notes - with Flex 5000A V/U, TS2K and IC746Pro

432/2M and 6M/222 Combined Stations Sept 2011 with FLEX 5000A - [PDF] - So few operators this time! Used Communications trailer.

In September, 2014 - we eliminated 222 and replaced it with 1296 to simplify the system further. Our scores were down, but we had a great time. [Except, I cut my leg loading a trash bag. The doc in Harrisonburg used 16 stitches to close the wound. Not good, when you're on blood thinners.] We bought new antenna systems for 2M and 432. M2 ants. 2M5WL has 16.84dbi of gain and 17 elements. The boom is 33' long. 432-9WLA has 19.44 dbi gain and 28 elements. The patterns are very clean. What a pleasure to use these new antennas. W4NF fronted the cash, but the team covered the cost. I assembled the antennas. 2M stacking distance 14' and 432 stacking distance 72".

432 Station

432 and 222 Combined Stations June 2011 with SDR 1500 - [PNG] - with AMPs remoted in WA0DYJ's van and a custom sequencer.

432 Station Diagram Sept 2010 with SDR 1500 - [PNG] - Uses TE Systems Amp

432 Station Diagram June 2010 with SDR 5000A - [PNG Graphic] - Experimental

432 Station Diagram 2009 with TS2K and MicroKeyer - [PNG Graphic] - OLD

432 Station Diagram with DVK and sequencer - [PNG Graphic] [Visio Drawing] - OLD

432 Station Diagram with MicroKeyer and sequencer - [PNG Graphic] [Visio Drawing]

432 Station Diagram with MK and No Sequencer - [PNG Graphic]

432 Station Diagram with SDR - [Visio Drawing]

432 Sequencer Timing Diagram - uses W7IY Custom Sequencer and Flex 1500 - [PNG Graphic]

432 Sequencer Timing Diagram (Verified) - [PNG Graphic]

Important 432 Notes

222 Station

222 Station Diagram with TS2K - [PNG Graphic] - Latest Stand alone See 432 for combined station drawings.

222 Station Diagram with DVK - [PNG Graphic] [Visio Drawing]

222 Station Diagram with MicroKeyer - [PNG Graphic] [Visio Drawing]

222 Sequencer Diagram - [PNG Graphic]

Important 222 Station Notes

  • http://www.microham-usa.com/Products/MK/Cables/DB37-IC-8.pdf - MicroKeyer Cable for the ICOM
  • June 2008 - used Flex 5000A and Electraft 222 Transverter.
  • Sept 2009 - changed the sequencing. The rig keys the sequencer and transverter using the same key line. The TS2K has an internal 25ms PTT delay. The transverter keys the amp. IC756 under repair. We let the smoke out.
  • June 2011 - we combined the 222 station with the 432 station because we don't have enough operators. See the 432 section for the current drawing.

2 Meter Station

2 Meter Station Diagram with MicroKeyer (2009) - [PNG Graphic] - Current

2 Meter Station Diagram with MicroKeyer - [PNG Graphic]

2 Meter Sequencer Diagram - [PNG Graphic]

Important 2 Meter Station Notes

  • WSJT - Configuration and other notes
  • The rig keys the sequencer, now. This should fix the problem we had with the sequenced preamp control. Also, set MH to SO2R, which moved the Winkey PTT to the Aux connector on the MH and the rig will not QSK. Although, at the end of Sept 2009, I blew another FET during the last 1/2hour of the contest. I was using full power CW.
  • http://www.microham-usa.com/Products/MK/Cables/DB37-IC-8.pdf - MicroKeyer Cable for the ICOM (Note this cable can be used on the 756 Pro (222).
  • Manual for the antenna (8 MB) - https://www.stu2.net/projects/f012assemblymanual.pdf
  • The SSB Electronics preamp uses MGF-1302, I know because we keep blowing them up in different ways.

6 Meter Station

No diagram for this station. In progress.

The station is usually an ICOM 756 Pro, DVK and Heathkit Linear. No preamps.

Computer Network

We use N1MM to link all the computers together. Over the years, we have tried a variety of configurations and logging programs. After a stint with Writelog, we switched to N1MM and it's been great.

Since 2012, we started using the link from Laird's Knob, which is a 2.4GHz link. Our end is a small wire dish with a Ubiquiti radio. (Don't know the model number.) This network has been very solid and very easy to use. Set it up, point the antenna and you're in.

Aside from the LAN environment, we also have an 802.11 wireless link from Flagpole to Harrisonburg. One of the local businesses in HB is kind enough to let us use their DSL and mount an antenna on their roof. (Funkhauser Realty) They've been great to us. We would really like to thank Brian and Todd for all their efforts to make this link happen.

I think we started the link after a visit from N4DSL. He inspired us to give it try. 2.4Gs didn't work so well, but 903 is excellent! The 2.4G link would come and go, but the 903 link is steady as a rock.

We also set up an AP for people in the 'camp' to check e-mail, etc. One year, we had an asterisk PBX link set up between the MT and VMCS in Woodbridge. We could make outgoing calls and take incoming calls. Cell phone service is iffy, so this was a nice service to offer.

If you have any questions, please contact W7IY. We've probably done it. ;)

Current Network Diagrams

The 900 MHz link was replaced because the other end moved out! Luckily, we have an 802.11 link to Lairds Knob, which is about a 23km shot. The LAN is still the same and we provide free 802.11 in camp, which lets us watch the weather maps and collect packet spots.

900 MHz Link used for June 2008. This worked very well. It was essentially an 802.11 high speed link using the XR9 cards from Ubiquiti, coupled with an rflinx 2W amp and 13dbi yagi. (Under Amateur rules. See http://www.qsl.net/kb9mwr/projects/wireless/plan.html for more info.)

Bearing to Harrisonburg Link: 109 True, 118 Mag. 28.46Km

Network - PNG - Current (June 2009 use the contest station LAN only) Need to update IP addresses. (102.151)

Mountain Node - PNG

Valley Node - PNG

Update: June 2009 - I wasn't able to go, but thanks to Todd, KI4GSS for setting up the link in Harrisonburg again. The link came up, once the antenna on the MT was pointed in the right direction. For the third time in a row, it was solid.

Old Network Diagrams

We usually network the contest computers together. Switching to N1MM (from Writelog) made this job significantly easier. The network isn't anything special, however there are a few key points:

  • We have experimented with connecting our LAN to the internet using two methods:
    • a long distance 802.11 link between Flagpole Knob and Harrisonburg.
    • a satellite connection using Tachyon satellite service (auto deploy system)
    • 903 802.11 link to Harrisonburg - this is our current and most stable configuration

Computer Network w/satellite connections - PNG

Basic Network with long haul 802.11 link - PNG


We currently use a Kohler 35 KW generator, which is mounted on a trailer. We need better diagrams to show the power layout. There are a lot of wild experiences trying to deal with power. WA0DYJ, KA4CKI and KT4AD are the power gurus. The Kohler is loud, but stable as a rock!

  • After blowing up several computer interfaces, we devised an isolated ground system to make sure the computer's ground floated at the same potential as the Rig's ground.
    • Cut the third wire ground on a power strip
    • Plugged the computers into the 'special' power strip
    • Connected the computer case to the Rig's ground
    • Feed the computer power strip with a UPS

Note - we no longer need the special power strips because the grounds are tied together in the club trailer. We use the small trailer exclusively. Great operating position. Warm and dry!

In 2019, we decided to use a 3500W generator to power the station. (Preditor, modified to use an external gas tank.) We were able to power the W6PQL Amps, but required 48V worth of sealed lead acid batteries floating across the power supply's output. The batteries absorbed the instantaneous load.


Here are the some of the latest manuals for the equipment we use in the stations.They are all local copies on my web server. (i.e. that means it'll be slow downloading them from my ADSL.) WA0DYJ started a manual gathering project and has a CD with about a GIG of useful info.

SP-7000 Manual

Micro Keyer Manual

SSB Electronics DCW2400 Sequencer Manual

ICOM 746 Pro Manual

Kenwood TS-2000 Manual

222 Transverter


Clouds and Moon over Harrisonburg
  • VHF June 2008 - Notes from June 2008
  • Suggestion - we need to document the antennas and the power systems to the same level as the stations.
  • Need a fail-safe on 2M - blew the preamp June 2009 AND again in Sept 2009 (too much power - I ran the AMP at full output CW at the end of the contest. Poof.)
  • VHF June 2009 - Notes about things to do as a result of June 2009, with some Sept 2009 updates.
  • VHF September 2011 - Trip report from the September 2011 contest.
  • VHF June 2014 - Trip report from the June 2014 effort. One of our best scores in a long time.