Category Archives: K9ZW Operations

Inside the RBOG Antenna

A Reversible Beverage On Ground (RBOG) Antenna in concept is fairly straight forward, but the details are a bit difficult to unearth.

Compared to an Elevate Beverage Antenna an BOG Beverage On Ground Antenna takes up a lot less real estate. Typical Beverage lengths for 160m are 1 to 2 wave lengths which works out to 524 to 1048 feet.

With extensive testing in actual field use, hams have found a 160m RBOG works well at 200 feet down to 160 feet. This would appear to nominally be only 3/8th wave length down to a bit less than 1/3 wave length. Some sources suggest this difference results from the ground interaction and there is the whole story of how the received waveform sort of “lays down” across a Beverage.

In practical testing hams report no increase in sensitivity and some report declining sensitivity for lengths beyond the 200 foot mark.

I’m aiming for more than 160 feet and as close to 200 feet as my location’s limits allow.

If you are are like me, the puzzling into what is inside the various parts for an RBOG setup will lead to opening things up.

Here are pictures:

Feed-End Transformer

The Transformer nearest to the Shack is where the particular RBOG Forward and Reverse sense are picked up:

 

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REPOST: Background FT8 Remote via SmartLink and SmartSDR for Windows (June 6th, 2019)

REPOST of a June 6th 2019 Post. EDITS in BOLD with Brackets []

Background FT8 Remote via SmartLink and SmartSDR for Windows

If you spend long hours desk-bound like I do, your thoughts may also wander to the question “Could I make some QSOs during work? [EDIT With the immense amount of screen time working (we’re considered an essential business at work) while in isolation making any QSO is a treat.]

Back in SmartSDR v1 days I started with a Raspberry Pi VPN using a Maestro during lunch hours. Those phone (SSB) QSOs were pretty few.  Fist I had limited time and then if staff knew I was in the building they had things to bring to my attention, which is hard to manage when you are also in QSO!

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First 2020 QSOs – SmartSDR for iOS and Flex-6600M

While a tame night out my family insisted in seeing the New Year in by staying up past midnight. All things led to rising late.

I wanted to catch the first QSOs of 2020 as I ate breakfast, and I used the iPad with SmartSDR for iOS to catch some FT8 traffic.

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Recoordination of the K9ZW 145.110 Repeater is Complete

The Manitowoc 145.110 repeater lost its coordination through an administrative trip up.

WAR (Wisconsin Association of Repeaters) decided at one point to drop formal communications and basically sent out a single email that essentially had to be replied to or coordination was forfeit. No physical mail, no follow up and about as lazy of a process as could be imagined.

I wasn’t notified of the coordination issue until over a year after they dropped it.  No “Bye Bye” notice.
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So What Are the New RF Exposure Rules in a Nutshell?

This notice was put up by our ARRL on December 5th and I’ve been puzzling about it since: (Link http://www.arrl.org/news/fcc-amending-amateur-radio-rf-exposure-safety-rules )

FCC Amending Amateur Radio RF Exposure Safety Rules

12/05/2019The FCC is amending its Part 97 Amateur Service rules relating to RF exposure safety. In a lengthy document in ET Docket 19-226 released on December 4 that addresses a broad range of RF safety issues, the FCC said current amateur radio RF exposure safety limits will remain unchanged, but that the amateur-specific exemption from having to conduct an RF exposure evaluation will be replaced by the FCC’s general exemption criteria. Radio amateurs have always had to comply with RF exposure limits, but certain stations have been exempt from having to conduct evaluations based only upon power and frequency. The Commission indicated that by and large, if an RF source was “categorically excluded” from routine evaluation under the old rules, it will most likely still be exempt under the new rules, which are expected to take effect in the next couple of months.

“For applicants and licensees in the Amateur Radio Service, we substitute our general exemption criteria for the specific exemption from routine evaluation based on power alone in Section 97.13(c)(1) and specify the use of occupational/controlled limits for amateurs where appropriate,” the FCC said.

“The sky is not falling here,” ARRL Lab Manager Ed Hare, W1RFI, commented. “The major aspects of the rules will not impose major new burdens on the Amateur Radio Service. As in all regulatory matters, though, the devil may be in the details, so the ARRL technical staff, legal staff, and the experts on the ARRL RF Safety Committee are carefully evaluating this FCC document.”
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Even in FT8 some station can overdrive and ruin your band reception

Not that one sees this that often, but it is possible to have another station’s poor signal basically wipe out your FT8 operations.

In this case someone was over-driving to the point their signal splattered wiping everyone else:

 

When another station is splattering FT8 transmissions

Typically in FT8 this resolves itself when after a bit they give up, as their signal usually can’t be decoded well without some attenuation and gyration.  So they move along.

It is not unreasonable for FT8 operators to run some power.  FT8 is a weak-signal mode, not a QRP mode.

But if they don’t have their station configured correctly the added power can lead to a mess.

(Notice in the picture that the overpowering signal was only the “even” transmissions as the “odd” ones remained regular looking signals.)

73

Steve

K9ZW