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Author Topic: FM works well on 160m  (Read 3630 times)

VK3YE

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FM works well on 160m
« on: September 01, 2018, 05:02:15 PM »

A video of a crossband involving 2m/80m/160m.  Most notable is the use of FM on 160m.  It works well for groundwave paths.

https://www.youtube.com/watch?v=sNcIUEvnSbk
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KM1H

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RE: FM works well on 160m
« Reply #1 on: September 03, 2018, 11:29:12 AM »

NBFM was used in the 50's especially mobile on 160 and 75 where ignition noise was high before resistor plugs and wires became common. It also reduced the 6VDC current draw on the generator/battery by eliminating an AM modulator circuit, and was optional on many TX and RX. It didnt really catch on and was gone by the 60's.

Carl
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N8YX

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RE: FM works well on 160m
« Reply #2 on: September 07, 2018, 07:22:02 AM »

In before the bandwidth hogsESSB crowd...
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AC7CW

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RE: FM works well on 160m
« Reply #3 on: September 13, 2018, 09:39:00 AM »

i'm a ragchewer as much as anything else. My best memories are from high sunspot times when I could talk to hams all over the world on 10M FM with a vertical on the roof. I'd use FM everywhere if I could, very much of the time the bandwidth is about a minus zero concern. Why all the obsessing about bandwidth? Especially on 10M where it's quasi-channelized... SSB sounds awful most of the time, I'd rather listen to CW...
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Novice 1958, 20WPM Extra now... (and get off my lawn)

KM1H

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RE: FM works well on 160m
« Reply #4 on: September 13, 2018, 05:20:44 PM »

In before the bandwidth hogsESSB crowd...

Also before a RF audio processor in every radio for all the knucklheads to crank up to 10
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N8YX

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RE: FM works well on 160m
« Reply #5 on: September 14, 2018, 06:33:54 AM »

...Also before a RF audio processor in every radio for all the knucklheads to crank up to 10

Interesting story about that:

I have a "Drake with haaandles" (actually, a TR7/R7 combo with mobile-style wraparound cases fitted). During one Field Day I decided to go all Drake, per a tale from a friend/coworker/ex-Drake Guy (Greg, W8XY). (Back in the day, he and a coworker figured out how to make the "Twins" work effectively as an SO2R or multi/multi pair, albeit with a shared mic and on the same band. Each op would use a set of headphones with their half of the Twins and the "RCT" button on the R7 was used to transfer control to it. This was very effective when the TR7 stayed put and the receiver was used to search-and-pounce.)

So...my FD setup consisted of a TR7/R7/MS7/MN75/PS7/SP75 and a 7077 mic. Stock TX IF chain in the TR7 (2.3KHz filter). I taught my co-operator the mechanics of the setup and put us to work. The SP75's compressor gain setting was on the order of just a couple of decibels...not even 9 o'clock on the control.

The pileups we generated were due to the audio. Many unsolicited reports during the event praising the signal quality, wondering both what I was running and how I set it up.

Also germane to this discussion area because R7 #8 is inbound and might be used as a LW/MW platform once gone over.  ;)
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KM1H

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RE: FM works well on 160m
« Reply #6 on: September 14, 2018, 05:23:03 PM »

In the mid 60's thru early 80's, when I got a TS-930, I used a Comdel CSP which was really a RF clipper but at a very low frequency. It was very clean and effective on phasing and filter rigs on SSB but setting the gain properly required a scope.....I used a Central Electronics MM2 in line modulation monitor

https://www.radioexperimenter.us/rm-1966-12/comdel-speech-processor-model-csp.html

I might still have it ::) and still use the MM2

Carl
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WB5WPA

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RE: FM works well on 160m
« Reply #7 on: January 31, 2019, 12:38:43 PM »

A video of a crossband involving 2m/80m/160m.  Most notable is the use of FM on 160m.  It works well for groundwave paths.

https://www.youtube.com/watch?v=sNcIUEvnSbk
Yes, it does!  :)

Some of my first tests on "proving out" the workability of a 1/8 WL circumference 160 m xmitting loop was through the use of a remote base to do crossband tx-rx on 160.

The original "test" 160m loop made out of 17 ga AL wire was 10ft high by 22 ft wide (64 ft circumference) held up by just four of those 4 ft mil tent poles on each end (no guys needed) and the loop was tuned with a modest air variable cap (per G0CWT's webpage) ...

The signal was easily readable 18 miles away on a 160 meter mobile receiver. The remote base radio transmitter was running just 25 Watts power in NBFM mode.

WB5WPA Jim
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