Meteor Scatter (MS) thriving

I have just returned to my favourite Amateur Radio propagation mode of Meteor Scatter (MS) and found that the 50 MHz (6m) band is absolutely full of activity and thriving more than ever with operators.

The new MS mode on the scene in 2017 is MSK144 mode with 15s intervals and appears to have completely taken over from the previous commonly used mode of JT6M, which was very prevalent as recently as 2015/16.

Most activity on MSK144 mode occurs around 50.280 MHz and the software in use appears to be either the long running and well known WSJT or the newer MSHV by LZ2HV.

Other frequencies seen are 70.280 MHz again with MSK144

This mode would also appear to be very suitable for Aircraft Scatter (AS) propagation and will be interesting to see how it performs there.

73 de Philip G0ISW

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Where have all the Amateur Radio technical conversations gone?

I became a SWL in 1983 and a Radio Amateur in 1985, back in those halcyon days we were not permitted to talk at all about Politics or Religion in case it caused offence and the vast majority of conversations to be heard were usually technically related to antennas, radios, propagation etc.

How things have changed now………..I have just been listening to 3.6-3.8 MHz LSB this morning using my Wellbrook ALA1530+ (modified to 100MHz) Active Loop Antenna and the range of non-technical conversations included:

Toe nail clipping, motorcycles & stolen cars!

On the positive side there were a few technical conversations overheard about:

IP cameras, OFCOM & RF breakthrough 

Not technical, but interesting was:

Stoats and wild rabbits & flooding

 

HF/VHF Mobile Operation

Well it seems that the VHF/UHF repeaters I have been complaining about having a lack of activity may actually have been more active than I had thought! Turns out my old Yaesu FT-857D radio had developed a fault with 2 out of 3 of its ceramic filters rendering my receiver virtually deaf except to very strong local signals. This is apparently a very common hardware design failure for this model of radio that has since been rectified with newer ones sold having different filters not subject to this problem.

Had my FT-857D repaired very quickly and cost effectively by the staff of Martin Lynch & Sons and it is like having a new radio in my vehicle once again, I also took the opportunity to have the radio modified to transmit on 5 MHz for portable operation too (mobile 5 MHz operation not being permitted here in the UK).

This has enthused me to be more active when mobile (or Portable) and using either a dedicated 144/432 MHz colinear or a Yaesu ATAS-120A for the 7-50 MHz bands or a dedicated single band 5 MHz aerial left me with the question did I have anything to use on the 3.5 MHz band?

A quick search in the garage resulted in me dusting off my old 0.9m long Australian Terlin Outbacker Stealth Plus antenna to see if it would tune around 3.760 MHz without an ATU so that I could potentially participate on the Worked All Britain (WAB) net. Many years ago before 1998 I used to be very active on the WAB net from my car on 14 MHz and drive all over remote mountain areas to activate the grid squares for WAB awards collectors.

Initially the SWR was found to be far too high and seemed high even at its lowest frequency around 3.5 MHz  I had added a 3/8″ to PL259 adaptor to the antenna which was part of my problem, the other was I had lost the original 36″ wander lead and had only a slightly longer lead available to me for shorting out the coils for the bands I want to operate on. Basically the aerial was electrically too long to resonate in the part of the band I needed.

I looked again at the Outbacker Stealth Plus and wondered if instead of using the 80M socket would the SWR be any better using the 75M socket nearer to 4 MHz? As luck would have it this worked with the tuning stub lowered to minimum and 1:1 SWR without an ATU seems to be around 3.740 MHz and still low enough at my desired 3.760 MHz.

Now I know people will say how can a 90 cm long antenna be efficient on 3.760 MHz? Well it can’t, however when I used this antenna before from home as a base antenna I had fantastic results with it, so I’m going to give it a go on the vehicle and see what happens!

 

 

 

 

 

RSGB confirms some British JT65/JT9 5 MHz signals out of band

Looks like my last post has had an effect……..

From RSGB News today

“Keep legal on 5MHz

The RSGB Amateur Radio Observation Service has noted several examples of
British JT65 and JT9 mode transmissions straying outside of the UK
allocated band slots.

It is understood that software commonly used by UK licensees for the
production of signals in both modes uses default 5MHz band preset
frequencies of 5.357MHz for JT65 or 5.359MHz for JT9.
After applying the audio offset to the AFSK signal in JT65 mode, using
these presets will, in the majority of cases, cause the transmission to
fall outside of the upper band edge of the UK allocation of 5.354MHz to
5.358MHz.
In the case of JT9, if the default of 5.359MHz is used then all
transmissions will be outside of the UK allocation.

Users of these modes are requested to check that their transmissions
fall within the allocated spectrum.”

UK Hams operating outside 5MHz band limits

This week I returned to the 5 MHz band and specifically the JT65/JT9 data section around 5.357 MHz.

Here in the UK we do not have a continuous 5 MHz band, it is split up into smaller allocated parts UK 5 MHz allocation and this ‘bandlet’ is 5.354-5.358 MHz which means no part of a UK Radio Amateurs transmission should be any higher than 5.358 MHz.

JT65 signals are 200 Hz wide so when operating on USB the highest frequency you can use in the UK is actually 5.357 +800 Hz or 5.357800 MHz otherwise your transmission will be above the 5.358 MHz maximum permitted.

It is clear from observing the UK 5 MHz band that some (new to JT65/JT9 data mode) UK Hams may not understand the band limits and how JT65 signals can easily be transmitted out of band.

Last night I observed two UK stations well above 5.358 MHz and transmitting well outside the permitted UK allocation. They were

M0N** JT9 5.358.57 MHz 16:34-16:40 utc 03.12.2015 calling A61BK

M1P** JT65 5.358.68 MHz 17:48 utc 03.12.2015, later seen at 5.359.0 MHz and also chasing A61BK

Screenshots of the HamSpots Cluster Spots page HamSpots were taken by me showing other Amateur Stations also reporting seeing both these stations clearly transmitting outside the permitted UK 5 MHz band allocation.

What concerns me the most is that this behaviour threatens all our access to the 5 MHz band as it only takes the primary user to observe this and potentially we could lose our access. Their working the DX station also would not be legitimate either.

Elsewhere in the World the JT65/JT9 activity is permitted from 5.357-5.361 MHz plus and they can operate without having to stay within our narrow 1000 Hz wide section that falls within the rest of the World’s allocation, but if they do we cannot call them back unless we transmit in our own allocation lower down in frequency and either encourage them to join us there or work split frequency.

Seen the next day

M0A** JT65 5.358.28 MHz 15:50 utc 04.12.2015 working PA0ING

G3J** JT65 5.358.18 MHz 16:29 utc 04.12.2015 working LA4CQ