This weekend during the annual 160 meter International Contest I experienced heavy interference on 1.840 MHz, up to 18 dB above my noise floor from 1.835 – 1.845 MHz, and knocking out some ten (10) lanes of potential CW operation during a once per year international operating event.
I also regularly encounter this same type of interference on 40 meter CW at 7.045 – 7.060 MHz where SKCC members and others operate slower conversational CW with straight hand keys/bugs and often antique radios. This is a small area of the band where CW skill building is commonly taking place – until you plop a 10 KHz wide noisemaker there.
In all cases this digital interference sounds like what I hear on 50.3 MHz – which is why I think it is the new modern digital modulation which some misinformed folks say causes no interference to other operators. I do agree that up on 50.3 MHz this causes no interference to the Beacons, CW, and SSB operation.
I have already written Bob W1YRC about this growing interference problem, and asked for escalation.
Apparently the suggested frequencies for digital operation include 1.840 MHz, so it’s no wonder I observed so much interference there +/- 5 KHz, and at times it was 18 dB above my noise floor. So much for the lies about these being low interference modes of operation, as they knocked out some ten (10) lanes of CW traffic.
There is no excuse however on 40 meters as the suggested frequency for digital operation is 7.074 MHz, and I am continually trying to receive through this interference on 7.050 and 7.060 MHz +/- 5 KHz each. This wipes out the SKCC activity area with some 20,000+ SKCC members.
I think it’s high time to re-address the suggested band-plan!!!
FT8 & FT4.
It’s FT 8 on 1840 and FT4 on 7047.5. On 160m there seems to be some of the 6 meter principle, that is, we are pushing the limit of propagation so we are justified in pushing the power. Whether or not it’s forgotten when back to working new jersey. The 40m FT4 frequency was a very odd choice, alas seemingly bound to annoy other established users. — Dave K1SX
According to Bob the band plan for digital on 40 meters is 7.074 MHz, so they should not be dropping down to 7047, 7050 and 7060 to operate digital. The Straight Key Century Club (SKCC) has over 21,000 members operating conversational CW with Straight Keys which are naturally slower than keyers – and which is a really good opportunity for operators, SKCC or not, to improve their CW skills whether they are new code-free licensed hams or older hams that are just a little rusty. CW operation is actually on the rise according to Bob, and part of the growth is apparently new hams, so a place that is naturally speed limited by hardware is good to have. The recommended frequency for SKCC operation on 40 meters is 7.055 +/- 5 KHz which is not very much to ask for considering the 21,000+ SKCC operators, plus others working them. However, it’s now being wiped out every evening by digital.
The 160 meter interference was just bad band planning, that probably goes unnoticed except for a couple of contest weekends per year – which I would think the courteous thing for the digital guys to do would be to simply QSY to another band for those 160 meter contests rather than hog 10 lanes of CW traffic on a band where many antennas have limited bandwidth.
Almost 5 years ago I found SKCC and it was my reason to start operating again with a straight key, and often with my vintage crystal rig (Johnson Viking Adventurer). It took me practically a year to get my fist back, and send clean CW with a straight key. I have had as much fun with SKCC as I had operating EME – which ironically I never rebuilt after moving to a place with real space for bigger arrays because I already did EME using my hand on a keyer and my ears in headphones for successful QSOs with 36 different stations around the world on 144 and 432 MHz, and was simply uninterested in semi-automatic computer to computer EME. I do my computer to computer email over 5GHz to my router and light down my driveway in a fiber optic cable…73, Chris WB2VVV