[Hobbes]

Supertechnological without using any actual technology.
Sure, sure 

You mean aside from the matrix.... No matrix, no resonance, no abilites.

Much like a mage needs mana. No mana, no magic, no abilities.


Remember, Technomancers are basically "technology magic users"... they need the baseline presence of the matrix, and thus technology, to do anything.

Drop that Technomancer into the middle of a matrix dead zone (the heart of a jungle, the middle of the ocean, basically anywhere there isn't civilization) and they lose all their abilites.

Would that be places where no local wireless networks exist?

RAW that all gets damn weird.  Mechanically "No Matrix" is really a million points of Noise, like under the water or the dark side of the Moon, deep in a cave, and such.  Anywhere else on the Planet is theoretically just a Satellite dish and 6 points of Noise. 

Even if a TM is someplace far away from civilization, if there are Devices near by the TM (or Decker) should be able to interact in some way.  At least RAW.  Unless the source of the Noise is also local.  (Worse Spam Zone Ever!) 

RAW there isn't any such thing as "Matrix Transmitters" that make the Matrix work inside some X radius.  Plot and Story wise occasionally derp around with such things.  And if they were mechanically defined, every Run would hit those first.  "Can't take a Host off line!??, Hold my beer!!"

It would certainly give all those Sniper builds something constructive to do though.   

[Jenny]

5 Net hits on a Matrix Perception or Assensing will let you spot a Technomancer.  3 Hits on Matrix Perception will let you spot a Resonance Signature on something that's been targeted with a Complex Form or Sprite Power or other Resonance ability. 

You really can't do much with a Resonance Signature, but it'll let an NPC spot something that's been whamied.   

Can you generally spot a TM with 5 net hits on matrix perception? The Flow Commlink in Kill Code mentions that you can do this, but page 241 in CRB (which it mentions) doesn't mention it. I'd assumed that it was an ability unique to the Flow Commlink.

[Hobbes]

p. 250: Core Book
Other Resonance beings (technomancers, sprites,
and ... others) can detect a Resonance signature by getting at least 3 hits on a Matrix Perception Test; noticing
a signature comes in addition to the usual questions you get to ask. If you’ve seen a signature before, you
can recognize it (the gamemaster might make you try a Memory Test, p. 152). With 5 or more hits, you also
get the impression of what kind of being or ability left it there (again, that info is free).....
....Resonance beings have their own signatures (with a rating equal to their Resonance) on themselves all
the time. A sprite has the Resonance signature of the technomancer that compiled it, as do the signatures
the sprite leaves.

And Kill Code p. 69
FREQUENCY RULES
The commlink provides a +5 dice pool modifir and +2 Limit
on Matrix Perception Tests to specifially identify an icon as a
technomancer. It takes fie net hits on a Matrix Perception Test
(p. 241, SR5) to spot a technomancer

Could be that the Frequency Rules are intended to be a specific ability of that Commlink, but p. 250 of the Core book says pretty clearly that Resonance beings have a Resonance Signature on their Persona at all times that can be noticed by other Resonance Beings.

So, a TM can spot another TM with 5 Hits generally.  Non-Resonance beings may need the Frequency Commlink depending on how you interpret the Kill Code rules on p. 69

[HP15BS]

p. 250: Core Book
Other Resonance beings (technomancers, sprites, and ... others) can detect a Resonance signature by getting at least 3 hits on a Matrix Perception Test;...
... With 5 or more hits, you also get the impression of what kind of being or ability left it there (again, that info is free)...
. . .
So, a TM can spot another TM with 5 Hits generally.  Non-Resonance beings may need the Frequency Commlink depending on how you interpret the Kill Code rules on p. 69

Well, a TM only needs 3 to spot that an icon has Resonance.  That alone may not technically be enough to distinguish between a sprite or TM, but since the possibilities are pretty limited, other things can clue you in pretty quickly.
Is Firewall 1 or 2 above a device rating of 6? Probably dealing with some kind of sprite.

And regardless, seeing active Resonance at all probably means another TM is at least involved.

[elbruce]

If you re-word the question to "does a Technomancer's persona show their own resonance signature," then I'd say sure.

[PingGuy]

In the end I went with the hand-wave, because it adds some higher stakes to the story.  The team is working a long-term job for MCT, and one of the team members is also (secretly) a TM.  If MCT were to find out there was a TM out there who could spot other TMs plain as day, they would go nuts over finding her.  Of course that could lead to more trouble than anybody would ever want to bring upon themselves, but that's a problem I'll have to solve another day.