Firstly, I need to extend a HUGE thank you to Paul AC2UQ as without his help, we were about to call it a day on HF during an NVIS HF test conducted by the USMA Cadet Radio Club after not being able to make contact with the very interesting Raven Rock Complex in Pennsylvania, but we did establish contact after a quick change.
I have a blank QSL card from W2KGY for you Paul when I see you next possibly with some special visitors, maybe next weekend at our OMARC RDF& BBQ?
With a noise floor of S5 just above and below the 20m, 30m and 40m bands using non-amateur frequencies, USMA spun down the dial and found the same issue which prevented Black Knight from hearing Raven Rock or much of anything else.
Looking to make some local contacts who could be above the noise, John W2JMU from the Orange County Amateur Radio Club and I started calling some local ham's on the phone to see if we could scare up some local HF people to chat with the W2KGY USMA station.
A quick conversation with Paul by phone before he headed over to Kenny's for the antenna party discovered we both had the same common noise on 7122 but not on 7250 or 14250 kHz. We still could not hear AC2UQ calling CQ, so what next?
Since W2KGY could not hear either AC2UQ or Bruce K2ULZ, moral was getting low. We even tried advertising where we were on the DX cluster and still could not raise anyone.
The "rag chewers" on 20m and 40m we could hear could not be bothered with us either, so as we started to swap out the Elecraft KX3 and Harris Falcon III PRC-150 to see if the Icom IC-705 would do any better, I discovered the source of the RFI after looking at the spectrum scope display and a rubber duck antenna...
Our goal was to save the battery for the PRC-150 for some other tests since they were not fully charged, so we needed a new plan.
The inverter generator pictured in upper right with the switching power supply on top of it proved to be the sources of the S5 noise floor, so I swapped everything over to run on my LiPo battery pack I use with the IC-705 when I need 10W seen pictured in a converted SLA casing and problem solved!
The KX3 worked perfectly afterwards and a few contacts were made with a few unsuspecting ham's in the north east.
We could NOT use the Elecraft amplifier since the puny battery we had would laugh out loud, so we were limited to about 8W of RF. So stop drooling at all this gear, we were at the mercy of the most basic things! Power and connectors!!
The antenna we were using was a Buddipole and the KX3 as we found that one critical "balun type of device" was left out of the official antenna kit which was a military equivalent of a G5RV style antenna. So we needed a quick field fix!
After using a part of my POTA antenna kit that converted from BNC male to binding post adapter, we were able to get the main antenna up and running. The inside of the MIL-STANDARD connector is the same as the BNC so things worked perfectly afterwards.
Did they make contact with Raven Rock?
Yes, it worked!! Tuning to a frequency outside of the ham bands, were we able to use an encrypted digital mode on HF for voice communications using a few watts to make contact.
Since transmitting at high power with easy to RDF signals is not very good for military operations, this low power and secure transmission requires a few seconds for things to be encoded and decoded on the receiving end. The end result was stunningly clear audio and a successful contact.
We also experimented with the pair of PRC-150 radios communicating with each other locally using a few of the encrypted modes that are not permitted on amateur radio spectrum. Feel free to google PC-ALE and the PRC-150 for more capability details to keep this post censor free.
What's next & lessons learned?
We have already learned this via past OMARC events, but summing up:
Know your gear
Know your connectors
Prepare for failure at any time
Improvise when needed
Still figure out how to communicate no matter what
There are some other exciting USMA things taking place really soon that you will hear about on the upcoming weekly nets and HVDN website, but please do keep an ear out for N2D during the Hudson River Radio Relay Featuring Bannerman's island on June 12th. USMA will be operating from Constitution Island with a clean power source, 100W of RF and some really good antennae on 17m, 20m, 40m and everywhere else listed at https://hudsonriverradiorelay.com/for-radio-amateurs.html
I am hopeful that N2H or K2OMD will be able to make contact with N2D (or W2KGY) during that great event this summer.
Hope you enjoyed this just as much as those really tasty looking chicken wings at Casa De K2KRP and sorry I could not be there (or be part of the morning 2m SSB test)
Upcoming Black Knight Balloon has moved forward to April 24th based on weather and other distractions so we may have some other things to RDF next weekend too beyond our own Foxes on 2m. Details to follow but subject to change. We will also likely be joined by some others from USMA not involved in the balloon mission, and "may" have some really fancy RDF gear for localized hunts at Ferncliff Forest.