Just talking about "frequencies" may be a misleading way to interpret "channel" disposition in the digital spread-spectrum "world", Gary.
When operating, any given receiver of an XD-V "channel" continuously interrogates its "mated" transmitter so that both of them can seamlessly "hop" between four separate frequencies in order to maintain uninterrupted reception of the robust stream of digital data that contains an encrypted "map" of our precious audio.
Broadly speaking, as I understand it, V75's have access to a full fourteen of these simultaneous "channels", whereas V70's can only operate within the first twelve of the fourteen and V30's only within the first six.
(A given transmitter will only be able to perform such "modeling" as pertains to its own "V series", regardless of whether it's being received by a V30, V70 or V75.)
As to an actual number of simultaneous "systems" that are possible, here's where things become a little weird.
I run two kits of four V70's.
Due to an operational oversight, I've inadvertently had BOTH kits spend a successful day working in close proximity to each other ("battery save" low power, ten metres apart, only separated by a vinyl-laminated timber divider that created two smaller conference venues from one large one), ...with each quartet assigned to (apparently "the same") channels one to four.
Here's what happens.
Each transmitter has its own "identity", a bit like a cell phone handset's "IMEI". When switched on, each one performs a "handshake" with the receiver on its nominal "channel" and from then on (until switch off or "drop out") that's the source recognised by that particular transmitter.
A second transmitter coming up on the same "channel" may limit the range of the first if brought close to that first receiver, but won't be allowed a recognition "handshake" until the first switches off, "drops out" or is actually swamped by more power from (and/or closer proximity to) the second.
Personally, I wouldn't deliberately set out to rely upon more than one system per channel.
Which makes the answer to "...can I operate 26 systems by combining them?" a definite, unequivocal "maybe" !
The new 14 channel systems operate on different frequencies than the original V70 systems. But unfortunately the way our system works they will almost certainly interfere with each other. You should only run RF1 (12 ch systems) or RF2 systems (14 ch systems) at a venue.
Thanks for clarifying that, Don...
I guess my earlier comments in this thread would still largely apply should earlier model transmitters have their firmware upgraded for RF2, with THH12's also gaining the unique benefit of V75's additional mic models.
As an aside, I've been around the world of showbusiness audio for a very long time...
So perhaps some credibility might attach to my saying that the immediacy and depth of support Line 6 provides here and elsewhere is unprecedented in my experience.
I'd also like to say that I'm in awe of Don Boomer and his colleagues' seemingly effortless competence and seemingly endless patience in speedily dealing with a myriad of issues and enquiries such as this.
Keep up the great work !
I now have 2 systems. One in the 70 series and one in the new 75 and plan to use both together.... At the same time. I also have 2 of the older 900mhz models. Should I and how do I update RF1 70 system? Gary
You can either switch the V75 into RF1 mode (instructions in owner's manual) or you can flash the V70 with V2.0 firmware. Once you have V2.0 firmware installed in your V70 you will have the option to use RF1 or RF2 mode depending on which will work better at your intended location. The V2.0 firmware includes RF scanning and RF efficiency tools to help you determine which would be best (although it is highly likely that either would work just fine).
RF2 mode should be selected when you need to use both XD-V wireless and 2.4G Wi_fi at the same time.
Instructions to flash old models are here in our "documents" section. http://line6.com/support/docs/DOC-2585
I bought the 75 thinking it might be better but now that I have one and I used it successfully to update the 70 model I will probably just buy a few more 70's. After some experimentation I have found, here in So. Florida that RF1 (70 series) works best and, I said and I like the line6 modeling mic best over the Shure, A/T and others. I have also tried putting on a SM58 head. I have used the Line 6 digital mic's without issue in the high RF traffic marina district and where jamming devices are used in many hotels and where most wireless mic's don't work, especially at night. That includes the 2 Line 6 XDR955 mic's I own.
I've taken a different route to a similar conclusion as Gary's, Gents...
In my case, (or, more accurately, cases) I'm very happy with my eight V70's that are "captive" in two Gator GM-4WR road cases.
They're "future proofed" via a "floating" V75 kit that gives me
- A ninth, stand alone, digital "chain";
- Access to either the 12 channel RF1 or 14 channel RF2 schemes for all nine and
- USB access for ongoing upgrades.