New US experimental station now operational on 40 MHz

[NI4Y]

So, what's the experiment?
Hams have 10 meters and 6 meters. Why spin this up on 40MHz? I mean, I get it, try a mode like WSPR on a quiet channel to see how it works, but I'd love to know the rationale for this...

Hi I saw this thread and thought I should respond. The difference between 28MHz and 50Mhz is quite a jump from a propagational perspective. The experiment is to gain understanding of the difference in E-Layer propagation and determine of E Skip forecasting can be developed. The process will be to send WSPR and FT8 on 10, 8, 6, and 4m to determine if a 10m opening leads to an 8m opening ect. Then evaluating the openings perhaps a better understanding of E Layer ionization can be gained. Forecasting of these types of openings can help not only the ham community, but the broadcast industry as well, who is often plagued by co-channel out of market interference in the spring and summer. Our happy E Skip time is the broadcast engineers headache.

This experiment can also allow the FCC to make decisions on how this spectrum is used in the future by gaining a better understanding of the propagational nature of the 40MHz band. That said this is not connected to or intended to be any sort of end run around an allocation, this is an experiment to see the different behavior of radio spectrum when the experiment is over it is over, but the understanding of F layer propagation may be explored if it appears to be relevant as the solar cycle increases.

Additionally no know two way transatlantic contact has taken place on 8m or 4m. At this time one of my 40MHz WSPR transmissions was received via multi hop E Skip in England. England does not have 40MHz allocated to hams so the receiving station could not transmit. The level was sufficient to have completed a FT8 and CW contact, but not likely to complete a SSB contact. I have conducted several unsuccessful attempts to contact Slovenia S5 who does have a 40MHz allocation. Ireland is a more likely candidate.

If anyone is interested in being a RX or TX station to be added to the experimental license please contact me I am good on QRZ NI4Y. RX equipment will be a home made fan dipole for 10, 8, 6, & 4m, a Raspberry Pi3 or better and an RTL SDR. Alternately a PC with a radio with SSB on 10, 8, 6, & 4m and the same fan dipole. Note 4m is going to be a bit tricky from a timing perspective and may be eliminated from the experiment. Further testing is needed to ensure no interference to licensed users occurs. Interestingly the main users of 72MHz pause transmissions for 30m each hour so this is very helpful. Equipment testing is on going.

If you're reading this far in the future check WL2XUP on QRZ.com for current details and experiment results.

73,
Lin NI4Y // WL2XUP
PS you said you would love to know LOL

 

[NI4Y]

ive know some to even use the 70-80mhz range

In general yes the DoD gets priority, however the 40.66-40.7 spaces is also allocated internationally to ISM so they generally stay clear of this space as they have the rest of whole 40-42MHz. As you say they do stray out of their assigned area in the US from time to time. Not sure if you recall but a very large Army Reserve exercise was conducted "inadvertency" in the 6m band. It was in the spring and was heard by hams up and down the east coast. Later the Army apologized for the error. Radio ops are trained, but you know 18-24 year reservists running around in the woods don't always do what they are trained to do even in the military.

 

[NI4Y]

I will have to give this a listen now that I am finally getting my low band antenna up.
A vertical omni so don't know if I will ever pick it up.

I was receiving myself on RemoteHamRadio.com with an OCFD give it a shot. WSPR is best it is on most of the time. USB dial Frequency of 40.662 and make sure to sync your clock to an NTP. I use BKTimesync it is important to decode WSPR using WSJT-X

 

[nd5y]

Most modern military low band radios cover 30-88 MHz.

 

[n8uad]

ive know some to even use the 70-80mhz range

I'm sure some do, but some of the radios in use won't support that.

 

[n8uad]

Most modern military low band radios cover 30-88 MHz.

The ones I worked with became degraded in the 70 MHz range.

 

[NI4Y]

My thinking exactly.



OK, so 4 meter band makes slightly more sense than 40MHz, but that doesn't align with the UK 4 meter band.

Still sounds like "I wanna play around outside the ham bands" than anything else. Not dissing the guy, just trying to figure out what the overall idea is.

I could not apply for 70MHz as the FCC has TV stations assigned in the area that EU has the 4m band. I have been discussing with EU Stations what frequency would need to be used to avoid their land mobile users and so that I can avoid interference to paging users on 72MHz. I recently purchased some of these clocks to see what impact transmitting when the bases stations are in rest cycle, part of their licensing due to the band being shared by RC hobbyists too. That said 99% of RC hobbyist tell me they are on 2.4GHz now. The interesting part about these clock transmitters is they go silent for 30m. This leaves a large window to conduct a cross frequency contact on 72MHz with EU stations listing there and TXing on 70MHz. While this is a fun idea the main focus as I said is understand propagation and if a 6m opening leads to a 4m opening and does that lead to a FM broadcast band opening. The latter is of interest to broadcast engineers who like the idea of the aprs system warning them of tropo ducting, but it is a bit to high in frequency to be reliable.

 

[KE5ZBG]

WL2XUP Callsign Page

From Wikipedia:

• active since July 21 2021. WL2XUP Experimental station transmissions are on 40.6635MHz (USB dial Frequency of 40.662) FT8 and WSPR are followed by a Morse code identification.

In a similar vane, the US-based 4 meter beacon: WG2XPN

 

[bryan_herbert]

Everything below 108 MHz, including HF, is now considered a tertiary or backup band.

UHF (225-400 MHz) is primary and VHF (138-144, 148-150.6, 162-174 MHz) is secondary.

Most aircraft, plus some ground troops, are also equipped with C and L band satcom gear which is where a good chunk of everyday traffic from the Global HF system 'Scope Command' has gone to.

All the branches use low band VHF between 30 and 70 MHz, in FM mode for interservice comms between ground pounders and airborne assets. Also the Army aviation units well as USAF aircraft use it for interflight communications between aircraft in the same flight. IE:Mud flight consisting of Mud 01, Mud 02, Mud 03, and Mud 04 will all use a frequency in that band to talk amongst themselves without interfering with ATC on UHF or VHF.

 

[KE5ZBG]

Quote"
I thought maybe somebody was trying to resurrect the original FM band with music stations back on the low band and trying out standard FM, DRM, DAB+, etc...?

The Armstrong Labs in Alpine NJ usually broadcast with a STA every October on a period correct resurected 40mhz FM transmitter that is beautiful, and looks like new. Music and some news casts of the day (1930-40's)are the main program. They ask listeners to call in on a website with signal levels. I don't have any 40mhz 75kc wide FM radios so I use my R2600D service monitor. Been able to receive with a good signal quality 30+ miles away.

For anything who is interested, here is one of their licenses: WB9XXE

 

[KE5ZBG]

Additionally WH2XND is operated on 75khz by NI7J (Scorpion antennas) from Arizona

Reception report

Also VK4RBC on 2200m from Australia

 

[AK9R]

1,230 km contact made between two US stations on 40 MHz.

Contact on the 40 MHz band in the USA between two experimental stations - 9th Jan 2022

9th January 2022: In the second half of 2021, a number of amateur radio stations in the USA applied for experimental permits for the 40 M...

ei7gl.blogspot.com

 

[jwt873]

Interesting.. I'm parked on 40.662 MHz right now listening for WSPR beacons.. Successful WSPR reports on the 40 MHz band in the USA - Nov 2021 Will give it a few tries over the coming days.

Wish I would have heard about this last night. There was a good sporadic E opening on six Meters around 03:00 UTC Would have been a good time to listen to eight Meters..