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  #41   Report Post  
Old October 14th 18, 08:32 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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On Sun, 14 Oct 2018 12:04:52 -0700 (PDT)
Jeefaw K Effkay wrote:

On Sunday, October 14, 2018 at 7:33:10 PM UTC+1, Jeff Liebermann
wrote:

It might help to understand why some bands use LSB while others USB.
In the early daze of sideband radio, the common IF frequency was
9MHz. The radios had only one sideband filter. With one filter, it
was cheaper and easier to mix and up convert in the transmitter.
So, to save the cost of adding a second filter, the bands below
9MHz were designated as LSB and the band above 9MHz became USB.
Eventually, radios were built with two sideband filters, and this
was no longer important. As usual, the legacy technology remained
in place to haunt the survivors to this day.


I've seen this explanation before, but it doesn't make sense.

A 9MHz USB signal mixed with a 5.0 to 5.5MHz VFO will produce mixing
products in the 80m and 20m bands - but both will be upper sideband.





crosspost reinstated.





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Old October 14th 18, 08:59 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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Default 4NEC2?

On Sun, 14 Oct 2018 20:25:28 +0100
Brian Howie wrote:

In message , Bernie
writes
On Sun, 14 Oct 2018 05:59:35 -0700 (PDT)
Jeefaw K Effkay wrote:

On Sunday, October 14, 2018 at 12:57:21 PM UTC+1, Geoff wrote:
On Sun, 14 Oct 2018 11:55:13 +0000
Spite sent a message from the other
side:
On 14/10/2018 11:44, Geoff wrote:
On Sun, 14 Oct 2018 11:39:58 +0000
Spite sent a message from the other
side:

On 14/10/2018 11:04, Geoff wrote:
On Sun, 14 Oct 2018 08:50:13 +0000
Spike lied:

On 14/10/2018 01:32, Jeff Liebermann wrote:

wrote:

Gareth once complained about a mobile CB set-up he
installed in a 4x4 couldn’t reach further than a
quarter mile. That’s all you need to know about
Gareth and radio.

He probably didn't need any antenna at 1/4 mile (400
meters).

snip interesting detection story

Stephen Thomas Cole, the PP, just after gaining his UK
Full licence by 'acing' all three exams, appeared on a UK
Amateur group asking which sideband he should use on 40m.
That's all you need to know about him and and his ability
with radio.

That sounds interesting - can you provide a link to that
post?

No. For some reason it's been deleted.

Then we only have your word that it ever exsisted. I choose
not to believe a word of it.

'It's been deleted' means it did exsist. You can't delete was
was never posted. You might ask yourself why it was deleted.
That's all you need to know about his ego and and his ability
with radio.




We only have your word for any of that. I choose not to believe
a word of it.

What STC actually asked was which sideband he should use for RTTY
on 40m.

Which is, of course, an interesting question as it's not something
that was covered in any exam, current or previous.

My $0.02 worth is that it doesn't matter, since an RTTY operator
will know that he needs to invert the received tones if he sees a
string of "46464646" instead of "RYRYRYRY"


Here's what was asked, and it wasn't posted no archive, or deleted,
or any of the other weak bull**** that Burt has bean spraying around:

"Was pottering at my radio last night, heard the scream of data
being sent and was triggered to revisit a long parked project;
getting going on RTTY!

Here's the hardware I'm using:

Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running
CocoaModem

I've got everything hooked up, have CocoaModem configured and
displaying a waterfall but when set to RTTY mode it's just decoding
gibberish...

Other than a couple of short spells at club days, this is my first
go at this and I have no idea what I'm doing... Any tips?"

https://groups.google.com/forum/#!or...-radio/MjriIIU
zuHA/_ityI76x0IMJ


Good old Burt.


For the record all the data modes including RTTY use upper sideband
all the way up from 136KHz . CW A1A is also upper sideband but there
can be advantages to be had by swapping to LSB to avoid
interference. F1A beacons seem to be a law unto themselves. You can
get quite good at reading inverted morse.

Amateur RTTY uses inverted tones and a different narrower shift
compared with commercial RTTY.

I don't know why your getting onto Steve about this as none of it is
the radio amateur courses or even online anywhere, unless some smarty
pants comes along and tells me it is. Ok it's in here for WSJT


It was Burt who was doing the 'getting onto' and when it wasn't going
well for him he introduced a new plotline about mysterious disappearing
posts and the character defects that could be at the root of the
disappearing posts.

I joined it to point out that the posts are still there and that Burt is
a liar and a ****ing idiot.




  #43   Report Post  
Old October 14th 18, 09:47 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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Posts: 209
Default 4NEC2?

On 14/10/2018 20:30, brian wrote:
In message , Gareth's Downstairs Computer
writes
Whereas such antenna predictors seem to feature in amateur usage,
does anyone, anywhere, in the world of amateur radio have an
understanding of the underlying principles involved in
predicting the performance of antennae, or have we all,
regrettably, become indistinguishable from
consumerist CBers or beginner licensees?


4NEC2 and EZNEC are* just a fancy front and back ends for NEC2 (and
NEC4) Engines.

Program description is here :-

https://ntrl.ntis.gov/NTRL/dashboard...tail/ADA956129.
xhtml.


Thanks for the heads up, Brian, but a quick glance suggests that some
revision might be necessary of my 3rd year uni textbook, "Fields and
Waves in Communications Electronics" by Ramo, Whinnery and Van Duzer.

ISTR it to be an excellent book explaining complicated things in words
of one syllable, but 46 years down the line, I might have a more
romantic memory of it in reality :-)


  #44   Report Post  
Old October 14th 18, 10:13 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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Posts: 662
Default 4NEC2?

In article ,
says...

I installed a few radios in White Freightliner tractors in the 1960's.
They were all positive ground 12V. I think they switch to negative
ground in about 1975. Many other older tractors were positive ground
but switched to negative ground in about 1954-56. I vaguely recall
conversion kits being sold at the time.

I've seen a few 24V electrical systems, but those were all in military
vehicles.

I have only ran FM ham rigs in a car. I used to ground the rig to the
frame and run the positive to a relay that comes on when the car is
started. Never had any alternator whine or problems. For about the
last 10 or more years I just plug into the lighter or accessory socket
in the car. My Toyota power on those sockets only come on when the car
is started.


You might want to put a voltmeter across the power connector going to
your radio and across the battery, and compare voltages in transmit.
Methinks you'll find a rather substantial voltage drop through the
cigarette igniter jack. Also, that connector was never designed to
handle a plug and jack connector arrangement. It's the only connector
that I know of that has a spring which pushed the plug OUT of the jack
and lacks a retention system.



Ok on the tractors being 12 volts. As I mentioned I did not know the
voltage but thought they were positive ground as the truck drivers kept
blowing the transceivers up when switching from the car to the tractor
and back again.

I did not put the voltmeter on the car,but a wattmeter shows the
transmitter is giving close to what it is suppose to put out. The
accessory jack is rated for 10 amps . This is for a transceiver that is
rated for 50 watts out.

I did melt out one of the inexpensive lighter plugs. It was made of
soft plastic instead of the hard type.



  #45   Report Post  
Old October 14th 18, 10:33 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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On Sun, 14 Oct 2018, Roger Hayter wrote:

Geoff wrote:

On Sun, 14 Oct 2018 08:50:13 +0000
Spike wrote:

On 14/10/2018 01:32, Jeff Liebermann wrote:

wrote:

Gareth once complained about a mobile CB set-up he installed in a
4x4 couldn't reach further than a quarter mile. That's all you
need to know about Gareth and radio.

He probably didn't need any antenna at 1/4 mile (400 meters).

snip interesting detection story

Stephen Thomas Cole, the PP, just after gaining his UK Full licence by
'acing' all three exams, appeared on a UK Amateur group asking which
sideband he should use on 40m. That's all you need to know about him
and and his ability with radio.




That sounds interesting - can you provide a link to that post?


I hope I am as open-minded as the next person, but it is really
stretching credulity to accept that anyone could actually find that
alleged fact remotely interesting.

To be fair, it isn't law which sideband is used, but "commaon practice".
That actually is about operating, and is a counter example, it doesn't say
anything about technical skill. There have to be endless things about
"operating practice" that should be on an exam long before "which sideband
to use on 40m?"


Though I do wonder why someone wouldn't just flip the sideband switch if
something isn't working right.

Michael



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Old October 14th 18, 10:46 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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On Sun, 14 Oct 2018, Jeff Liebermann wrote:

On Sun, 14 Oct 2018 08:50:13 +0000, Spike
wrote:
Stephen Thomas Cole, the PP, just after gaining his UK Full licence by
'acing' all three exams, appeared on a UK Amateur group asking which
sideband he should use on 40m. That?s all you need to know about him and
and his ability with radio.


For what it's worth, I don't know which sideband to use on 40m. That's
because I don't operate much on 40m and don't have such details
memorized. I use a wall chart with the appropriate modes,
frequencies, sub-bands, and dedicated frequencies listed. Oddly, I
was able to pass the US extra-class license without knowing or
studying any of this. I believe I posted the story previously, but
it's interesting enough to repeat again.

There was a time when SSB transceiver used mixing schemes so it would
always be the "right" sideband when you switched bands. Even rigs that
had a lsb/usb switch would sometimes color code so you knew which sideband
was "right" for each band.

I suspect more recent rigs, with synthesizers and computers, they surely
default to the "right" sideband when you switch bands.

As I recall, when I was a kid, I knew from reading which sideband got used
on which band, SSB was hardly knew then but it was still "new" enough that
it got talked about in the magazines. But with an SP-600 and a tuneable
BFO, I had to tune the BFO both sides of zerobeat to figure out which
worked for which sideband, no convenient crystal controlled BFO marked
"lsb/usb".

If there was a question on the tests about this sort of thing, it would
likely show some frequencies and you'd have to figure out after
heterodyning which sideband you were on.

Michael
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Old October 14th 18, 10:51 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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On Sun, 14 Oct 2018, Jeff Liebermann wrote:

On Sun, 14 Oct 2018 18:50:34 +0100, Brian Morrison
wrote:

On Sun, 14 Oct 2018 10:42:24 -0700
Jeff Liebermann wrote:

For what it's worth, I don't know which sideband to use on 40m.


For data modes it's just about all USB, and has been for some time.
But it's easy to see why people can get confused and wonder what they
set up incorrectly.
No need to beat anyone up about it, just explain if you're asked.


I don't think I'm beating up on anyone, but if an explanation is
required, I can do that.

It might help to understand why some bands use LSB while others USB.
In the early daze of sideband radio, the common IF frequency was 9MHz.
The radios had only one sideband filter. With one filter, it was
cheaper and easier to mix and up convert in the transmitter. So, to
save the cost of adding a second filter, the bands below 9MHz were
designated as LSB and the band above 9MHz became USB. Eventually,
radios were built with two sideband filters, and this was no longer
important. As usual, the legacy technology remained in place to haunt
the survivors to this day.

Actually with filter rigs, they used only one filter. Military rigs might
use two filters, obviously especially if they did ISB, and there must have
been some ham rigs, high end, that used two filters, but generally it was
one, and the BFO crystal was switched.


There's more to this story, but I can't remember at the moment.

Michael
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Old October 14th 18, 11:01 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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Posts: 662
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In article , lid says...

On Sun, 14 Oct 2018 12:04:52 -0700 (PDT)
Jeefaw K Effkay wrote:

On Sunday, October 14, 2018 at 7:33:10 PM UTC+1, Jeff Liebermann
wrote:

It might help to understand why some bands use LSB while others USB.
In the early daze of sideband radio, the common IF frequency was
9MHz. The radios had only one sideband filter. With one filter, it
was cheaper and easier to mix and up convert in the transmitter.
So, to save the cost of adding a second filter, the bands below
9MHz were designated as LSB and the band above 9MHz became USB.
Eventually, radios were built with two sideband filters, and this
was no longer important. As usual, the legacy technology remained
in place to haunt the survivors to this day.


I've seen this explanation before, but it doesn't make sense.

A 9MHz USB signal mixed with a 5.0 to 5.5MHz VFO will produce mixing
products in the 80m and 20m bands - but both will be upper sideband.






When the 9 MHz is mixed with the 5 mhz the 20 meter signal is upper
sideband. The 80 meter signal is inverted and becomes the lower
sideband NOT usb. Years ago when ssb was just starting out on the ham
bands this made 80 meters and 20 meters easy and inexpensive compaired
to other methods. So it was decided on by hams to use 40 metes and
lower frequencies as LSB and 20 meters and above as USB. Then the
government stepped in for the 5 and 10 MHz bands and dictated what to
use.

For other reasons most digital is in the USB mode for all bands except
for RTTY. RTTY is usually used in the LSB mode for all ham bands, but
can be used in the USB mode if the tones are inverted. The commercial
RTTY was usually inverted from the normal ham RTTY.



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Old October 14th 18, 11:36 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
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On Sun, 14 Oct 2018 08:50:13 +0000
Spike wrote:



Stephen Thomas Cole, the PP, just after gaining his UK Full licence by
'acing' all three exams, appeared on a UK Amateur group asking which
sideband he should use on 40m. That’s all you need to know about him
and and his ability with radio.




Burt, I think that could've gone a bit better, Burt.


Burt, Thanks, Burt.




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