Off-the-grid communications

[Fansome]

I have only listened to bits and pieces of this, but it sounds interesting. The Grenade is mentioned at about 7:07 into the talk. I'd be interested to know who these guys are and how they got hold of a Grenade.

For the uninitiated, a Grenade is a legendary 10w AM HF transmitter, built by a pirate known as Radio Animal back in the 90s. From what I know, no more than few dozen were produced, and there seem to be maybe a half dozen or less still in use by a small number of pirates today.

Message: 1
Date: Wed, 28 Jul 2010 10:56:58 -0400
From: The Doctor <drwho@virtadpt.net>
Subject: Re: [Spooks] Spooks Digest, Vol 78, Issue 26
To: Shortwave Spy Numbers Stations <spooks@mailman.qth.net>
Message-ID: <4C50453A.9050407@virtadpt.net>
Content-Type: text/plain; charset=ISO-8859-1

-----BEGIN PGP SIGNED MESSAGE-----
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Beaumont, Paul wrote:

> Embassy radio equipment, especially from the Iron Curtain, is nothing
> like Ham or in some cases, Military gear. It can be accessed remotely,
> reprogrammed and retransmit messages without any human intervention.
> They are really nice bits of kit too.

A couple of years ago at a conference (The Last HOPE, July 2008) there
was a panel on unusual communications methods ("Off the Grid Voice/Data
Communications", by bernieS and Skip Avery, and I think one or two other
people). Near the end of the panel one of the presenters held up a
shoebox sized shortwave transmitted that he called a grenade (if he gave
the official name for it, I don't remember what it is off the top of my
head). It was claimed that they were very sturdy and had been used to
set up numbers stations a few times in the past.

I don't know anything else about it, but visually it seemed to fit the
description of military RF gear: big, sturdy, chunky, and probably able
to take a 20 foot fall without breaking.

If anyone's interested, the audio of the presentation can be downloaded
(officially, legally, and for free) from here:
http://www.thelasthope.org/media/audio/64kbps/Off_the_Grid_VoiceData_Communications.mp3

It's near the end of the recording; if anyone knows anything more about
this transmitter I'd be interested in asking a couple of questions about it.

- --

The Doctor [412/724/301/703]

PGP: 0x807B17C1 / 7960 1CDC 85C9 0B63 8D9F DD89 3BD8 FF2B 807B 17C1
WWW: http://drwho.virtadpt.net/

"For my next trick: anvils." --Harry Dresden

[This message has been edited by Al Fansome (edited July 28, 2010).]

[outhouse radio]

Very nice AL !    I have heard some of this somewhere before can't remember where !!   I got to looking in my computer i still had the audio file !!! 

[Seamus]

I've seen at least a few sites that purport to have the schematics of a grenade transmitter, though I haven't really taken a good look at any of them, and certainly haven't compared their contents.  Since original grenades are so scarce, maybe they had built one from one of these reverse-engineered sets of plans and, since the schematics were touted as being those of the grenade, they called it a grenade transmitter.  Similar to the way that someone would call a transmitter a corsair, or a mighty-mite, based on the label of the design that they built their unit from, or the way that people will refer to a modified or cloned antenna as a G5RV or hamstick dipole based on the original specs even though strictly speaking, that isn't exactly what it is.  Or, for that matter, how xerox, coke, or cuisinart are used to refer to items in their particular class, even though they actually represent just one part of that group.

...or maybe they _do_ have one of the original grenades.  I don't know enough about it (or the presentation in question) to say.

[Fansome]

My understanding is that Radio Animal went to great lengths to keep the design secret. He never released any schematics or other design documentation. He even went so far as to file the part numbers and other identification off of the components inside the Grenade, and added some components that actually did nothing.

I have seen many projects mentioned over the years that purport to have copied the Grenade, but really the only one that seems to have had any success is the Corsair, and I believe that its designer does not claim to have copied the Grenade, only to have been "inspired" by it.

I've seen at least a few sites that purport to have the schematics of a grenade transmitter, though I haven't really taken a good look at any of them, and certainly haven't compared their contents.  Since original grenades are so scarce, maybe they had built one from one of these reverse-engineered sets of plans and, since the schematics were touted as being those of the grenade, they called it a grenade transmitter.  Similar to the way that someone would call a transmitter a corsair, or a mighty-mite, based on the label of the design that they built their unit from, or the way that people will refer to a modified or cloned antenna as a G5RV or hamstick dipole based on the original specs even though strictly speaking, that isn't exactly what it is.  Or, for that matter, how xerox, coke, or cuisinart are used to refer to items in their particular class, even though they actually represent just one part of that group.

...or maybe they _do_ have one of the original grenades.  I don't know enough about it (or the presentation in question) to say.

[Seamus]

Ah, right - now that you mention it, I do recall reading somewhere about some of the tricky business that went into obscuring the design of the grenade transmitter (it was a long time ago, and I was working the midnight shift, so memory wasn't exactly my strong suit at the time).  I remember being impressed at things like discreetly bypassed componentry, disguised components, etc.  To a point, I can understand wanting to avoid direct cloning of a design, though on the other hand it sort of works against the whole "free radio" thing in a way.

Everyone's got their own approach, I suppose...

[SW-J]

My understanding is that Radio Animal went to great lengths to keep the design secret. He never released any schematics or other design documentation. He even went so far as to file the part numbers and other identification off of the components inside the Grenade, and added some components that actually did nothing.

...

I hate to say it, but, anyone 'versed in the art' could put something together something in the way of a 'design' in an afternoon ... and this is not even considering the publications put out by 'The League' (ARRL) the last umpteen years that cover the subject of low-power/QRP transmitters ... never mind the Heathkit/Heathkit manuals and that equipment that can serve as the design guide for transmitters ... and countless solid-state CB radios from the 70's onwards that came with a schematic in the manual ... one would be HIGHLY surprised to really see anything novel 'rolled out' contain any real secrets ...

The crystal osc stage, a mult or gain stage or two, the PA, a push-pull audio modulator (ala CB radio) or even a series-transistor modulator (like a lot of 28V aircraft radios use) ...  impedance matching between stages ... the output lowpass filter; little of this is new or novel for decades now, esp in the 10 Watt power class ...

Just sayin ...

[syfr]

"My understanding is that Radio Animal went to great lengths to keep the design secret. He never released any schematics or other design documentation. He even went so far as to file the part numbers and other identification off of the components"


I recall hearing similar things at the time (late 80's?) and could never understand this behavior if true.  OTOH, as you note, there's hardly any secrets involved in QRP transmitters...even less so today. Why in the world would you not want to help out your fellow pirates, I wonder? It's not like there's a mass market for this stuff.