View Full Version : Slot in Wireless Mic Receiver - Channel 70


Graham Kay
February 26th, 2023, 02:43 AM
Hi

I'm looking for a dual channel slot in receiver that uses the channel 70 frequencies that are free to use here in Europe, to use in my Sony ENG camera with Sennheiser G2 packs.

Information is hard to find! Does anyone know which models - if any - offered this channel?

Alternatively is it true that these receivers can be modified - ie if I got hold of a channel 69 receiver could it be modded to channel 70. I'm guessing this wouldn't be a DIY job and could turn out to be expensive if done by a service centre!

Thanks

Rick Reineke
February 26th, 2023, 10:41 AM
The G series transmitters are not really compatible with other manufacturers or a different series receivers. If the frequency is the same, it can work if the pilot tone and the compander are disabled but it would not be as efficient and the sound quality would be degraded. It may be good enough for a scratch track or IFB though.
The G series portable Tx/Rx can be modified to use detachable SMA antennas which is relatively cheap and easy with electronic soldering skills.

Paul R Johnson
February 26th, 2023, 04:33 PM
The snag is the cost of slot-ins is crazy, always has been. The 6042 Sennheiser at nearly three grand I don;t think ever was sold in a channel 69 version. G2 and G3 ch 69 kit covers 70 too, but of course won't slot in. Is the slot in feature a deal breaker? I guess you could perhaps find a second hand one - and I'm pretty sure the ch 69 ones did 70? Trouble is slot ins were pretty TV specific and when new tended to be on the lower TV bands anyway - most broadcasters avoided ch 69, so their Sony's and Sennheisers were all on the lower bands.

Christopher Young
February 27th, 2023, 10:52 AM
For what it's worth. Not answers you want to hear, no doubt, but this was my experience with the whole wireless conundrum in the UK and Europe.

As far as I am aware, Sennheiser never made any of their slot mount pro receivers to work in the unlicensed Channel 70 band. I faced exactly this problem when filming in the UK four years ago as I wanted to hire a suitable slot mount for a PDW-F800 as technically our Aussie units frequencies were illegal to use over there. No such luck. The EK 6042, which will work with a wide range of their TX units, was only available in the licensed range of 470 to 654 MHz.

But what I did find out was that, quote:

"Program Making and Special Events (PMSE) audio users within the UK will retain access to the guard band (694 MHz to 703MHz) but will lose access to other frequencies in the 700MHz range from May 1, 2020."

https://www.telecomtv.com/content/spectrum/everyone-wants-a-slice-of-spectrum-and-etsi-s-lsa-might-be-the-answer-35749/

Now I had two sets of Sony dual diversity wireless receivers and mics that operated in the 700 MHz band as that band was the ACMA (like OFCOM) licensed frequency band in Aussie for us TV wireless mic users. Interestingly, the guard bands, 694 MHz to 703MHz were useable. Sure, that is a severely restricted number of useable frequencies left available. But in practice we used these guard band frequencies all over London and the south, Kent to Cornwall and had no issues at all.

I'm sure you may find a Sennheiser slot mount channel 69 700 MHz receiver at a reasonable price as most networks etc moved on from the 700 MHz band.

I would be checking with OFCOM for the latest updates on PMSE operators using these 700 MHz guard bands.

https://www.ofcom.org.uk/consultations-and-statements/category-1/700-mhz-guard-band-pmse

I looked at getting my dual diversity 700 MHz Sony mic sets re-worked with new frequency crystals, but the price was totally crazy. I can buy whole new digital systems for the price it was going to cost to rework the Sony kits. And no longer owning a slot mount camera put that idea to rest.

Just as a side note which may be of interest is the sound op on our last European trip took along a couple of RODElink wireless kits (2.4 GHz) as backups just in case. Running those all over the UK, Europe, London, Paris, Berlin and Cologne, in the most congested wireless environments you could imagine, we just downloaded a Wi-Fi monitoring app, and we had not one drop-out on PTCs and interviews when we used them in Europe. What was good about them is that they only had a 4ms latency, which was totally livable with when mixed with cable boom mics and the Sony kits, which had a 3ms latency. Whereas when we checked out the Sennheiser 1880 - 1930 MHz AVX system they had a 19ms latency making it an audio slip and slide nightmare in post when mixing with cabled booms.

Chris Young

Andrew Smith
February 27th, 2023, 04:41 PM
Another vote for the RODElink. Bought one and never looked back.

Andrew

Paul R Johnson
February 28th, 2023, 12:50 AM
Yes but we are talking about slot ins, so there is tons of choice if you go to other kit. Here, the government paid good compensation to kit owners who had incompatible kit when they changed the atavistic channels, so there's little on sale outside the licensable stuff.

Christopher Young
February 28th, 2023, 03:12 AM
Sadly, that's all a bit tricky, then. As I said, I looked at getting mine fitted with new crystals, but the price was prohibitive. It meant both TX units and the RX unit having to be retrofitted with frequency compliant crystals. It just wasn't worth it. Sadly, it has meant that two complete kits ended up on the shelf useless. Only the Lav mics have moved on.

The new Sony UWP-D27 Dual TX & RX Wireless Microphone System complete with two TX units and a dual channel RX and two Lavs can be had here for under AU$2000.00. Plus, they can be used with Sony's Multi Interface Shoe with a digital audio interface. That's a whole $1000 less than I paid for one TX unit back in the day. Basically, I think we can say the slot mount receivers are a thing of the past unless you want to pay Sennheiser / Lectrosonics type $$$'s.

Chris Young

Gary Nattrass
March 9th, 2023, 10:03 AM
As others have said the cost of these receivers are quite high so I have never invested in one and don't thin k I have seen a ch70 one either.

What I did do on my Panasonic P2 camera is wire the inputs up from the 25 pin D type connector in the slot to a couple of flying leads that I could then plug into my two G2 radiomic receivers.

The advantage then was that I could leave them rigged to the camera all the time and it also allowed the XLR's on the back to be available all the time too.

David Peterson
March 27th, 2023, 12:55 AM
The snag is the cost of slot-ins is crazy, always has been. The 6042 Sennheiser at nearly three grand.

That's very normal pricing for professional wireless. It's not crazy.

David Peterson
March 27th, 2023, 12:58 AM
Sadly, that's all a bit tricky, then. As I said, I looked at getting mine fitted with new crystals, but the price was prohibitive. It meant both TX units and the RX unit having to be retrofitted with frequency compliant crystals. It just wasn't worth it. Sadly, it has meant that two complete kits ended up on the shelf useless. Only the Lav mics have moved on.

The new Sony UWP-D27 Dual TX & RX Wireless Microphone System complete with two TX units and a dual channel RX and two Lavs can be had here for under AU$2000.00. Plus, they can be used with Sony's Multi Interface Shoe with a digital audio interface. That's a whole $1000 less than I paid for one TX unit back in the day. Basically, I think we can say the slot mount receivers are a thing of the past unless you want to pay Sennheiser / Lectrosonics type $$$'s.

Chris Young

Sony UWP series is the best prosumer wireless a person can buy on a tight budget, better than the Sennheiser G4 wireless.

Plus Sony makes a slot in receiver for their cameras (such as the Sony camera that the OP is using I presume), which could make this an even more attractive option:

https://www.bhphotovideo.com/c/product/1245557-REG/sony_urxs03d_14_uwp_d_portable_two_channel.html/BI/2855/KBID/3801

They also have a professional grade slot in receiver as well:

https://www.bhphotovideo.com/c/product/1508647-REG/sony_dwr_s03d_slot_in_digital_wireless_receiver.html/BI/2855/KBID/3801

(I use the Sony DWX digital wireless myself)

Graham Kay
April 11th, 2023, 04:02 PM
Thanks for the replies and advice, everyone. Having taken all that onboard I opted to upgrade to the newer versions of the Sennheisers I've been using forever. So goodbye channel 70.

I really like Gary's idea of using the connector in the slot to break out to the receivers. That's really neat and should be an easy enough job.

In fact, any tips on this would be great - which pinout to follow, etc.

Thanks again.

Graham Kay
April 12th, 2023, 08:47 AM
What I did do on my Panasonic P2 camera is wire the inputs up from the 25 pin D type connector in the slot to a couple of flying leads that I could then plug into my two G2 radiomic receivers.
Did you try also powering the receivers from the slot? According to the pinouts I've seen, there is +7v available and I would imagine the two body pack receivers are not going to draw more power than one of the slot in receivers (maybe 500mA togther?).

There are various dummy AA battery DC adapters available - including one from Sennheiser with a wide input voltage range.

I have various other power out options from my camera, but this would be neat if it works.

Gary Nattrass
April 12th, 2023, 09:08 AM
No I didn't power the G2 receivers but a good idea if you can do it as they will draw very little as you say.

I just use AA on mine.

I did also think of installing a couple of XLR sockets on the slot plastic cover plate but never got round to it so just had flying leads.

David Peterson
May 2nd, 2024, 12:34 AM
The snag is the cost of slot-ins is crazy, always has been. The 6042 Sennheiser at nearly three grand I don;t think ever was sold in a channel 69 version. G2 and G3 ch 69 kit covers 70 too, but of course won't slot in. Is the slot in feature a deal breaker? I guess you could perhaps find a second hand one - and I'm pretty sure the ch 69 ones did 70? Trouble is slot ins were pretty TV specific and when new tended to be on the lower TV bands anyway - most broadcasters avoided ch 69, so their Sony's and Sennheisers were all on the lower bands.

Older secondhand slot in receivers are shockingly cheap.

Plus slot in receivers (especially those which are SuperSlot) are the closest thing we have to an "industry standard" when it comes to receiver form factor for us Production Sound Mixers.

They're VERY popular, I myself own about ten plus of them.

Paul R Johnson
May 7th, 2024, 02:34 PM
The OP wanted licence free operation, and I've not seen any slot in receivers turn up on ebay in ch 70 versions. Channel 69 from time to time, but I doubt there ever were ch 70 variants. Sennheiser radio systems, especially packs got for pretty daft price for old gear.