Sennheiser 2012 Transmitter

[robertor]

Hey all,

I have searched the web for info on this kit, but nothing has turned up! Maybe because it is 20 years old or so!

I have 6x Sennheiser SK2012 Beltpacks and a Sennheiser Reciever rack system using modules. It is all pretty old stuff.

I have been usingthem in the theatre today and we are getting loads of problems with them.

 

We have brand new MK2 mics and new Sennheiser arials for the transmitters. They have Duracel new battieres in them all.

There is an unmarked rotary switch on the top of the transmitter, which switched from 1 to 8. What is this dial?

I presume the "LIM." switch is a limiter. They operate on 190 - 220MHZ roughly, so I asume they are VHF.

 

I cannot find a model for the recievers, but they consist of a rack mount system, containing 6x Modules of what seems to be something like EM2003. They have similar switches and display to the EM2003. There is a dial which reads "mV" and ranges from 0 to 100. I presume this is squelch?

Is there any gain control on the transmitter or recivers?

 

If anyone has any info on either product I would be most greatful, I can post photos if it helps.

Many Thanks

[minty]

There is an unmarked rotary switch on the top of the transmitter, which switched from 1 to 8. What is this dial?

 

I used some old Sennheiser VHF stuff recently, I'm afraid I don't know the model, however it had a 6 or 8 position (I forget) switch on the tranni and receiver which selected the channel. It sounds like you may have something similiar here. Although I don't know for sure! (Well that was bloody helpful!)

 

Best of luck!

 

Martin

[robertor]

Adjusting this rotary switch does not seem to effect the channel of the transmitter. It still transmitts on the same frequency.

[David Duffy]

Adjusting this rotary switch does not seem to effect the channel of the transmitter. It still transmitts on the same frequency.

A lot of transmitters only set the channel upon powering up. If you change it while running it won't change to that channel until it's been powered down and up again. It's a trap I've fallen victim to. (once!)

[Dave]

It sounds like everyone apart from me is too young to be familiar with this kit!!!

 

What you have is a very high-quality radio mic system that would have cost a king's ransom in its time. They were generally used in high-end applications like west-end shows or TV studios (few else could afford them).

 

The eight position switch is the transmitter gain control. All your other assumptions are correct - the "lim" switch is indeed a limiter, the frequencies are VHF, and the mV control on the receivers is the squelch.

 

This equipment was designed before frequency synthesised radio mics were around and so channel selection is done in hardware by changing crystals - it's a specialised job as I'm sure you have to realign the RF circuitry as well. You should find that each transmitter and receiver has a label on it giving the frequency.

 

Roberto, exactly what sort of problems are you having? You don't say!

 

More generally, all radio mics benefit from a periodic service. Tunings can drift over time for a variety of reasons (temperature changes, shock/vibration, component aging, etc). If your system hasn't been serviced in the last few years, now is probably a good time.

 

Sennheiser have a UK office in High Wycombe and I'm sure they could do this and supply any info you need on the system (such as the instructions!). Alternatively, Autograph are very good with Sennheiser radios.

 

HTH

 

Dave

[jimbo7744]

Another company that may still stock them and service them is:

Better Sound

31 Cathcart Street, London, NW5 3BJ

Tel: 020 7482 0177

http://www.bettersound.co.uk/service&repair.htm

 

Speak to Michael Collumb. They have been going since the 60's supplying radio mics and mixers to the TV industry and rarely throw anything away so may have spare parts if you need them!

 

Jimbo

[paulears]

I'd second Dave's comment about getting a service and using them. Built like bricks, and in their day, one of the best of the kind - well worth putting into action once given a little loving care. VHF being 'old' often gives you access to a few problem free channels as other people, and the bog-standard cheap radio mic brigade have moved on to UHF, leaving you a batch of underused channels. Rather handy to have up your sleeeve when you run out of UHF possibilities with more modern, brought in kit.

[robertor]

Thank you for all your input. The issues I was having were signals kicking in and out, a problem which will be resolved with turning the Squelch down to zero. I will also play with the gain control. I will get in contact with Sennheiser and get them serviced. They are looking a little battered especially on the recivers. The transmitters are in very good nick. I experimented with arial placement and it has sorted many of the problems with noise and hiss.

 

Thank You

[StevieR]

Before you start on the servicing, it may be worth checking the frequencies you have. Have a look for the frequency labels as Dave mentioned. Check if the frequencies you have are for de-regulated use or if they require a license. Go to the JFMG website for more information on this. If you find that you are going to need to change the frequencies then you may find this adds to the price considerably as the crystals will need to be changed.

 

Steve

[dbuckley]

Yaas. And as memory servers there are only five available frequencies in the licence free VHF band...

[Simon Lewis]

Yaas. And as memory servers there are only five available frequencies in the licence free VHF band...

 

And, 'helpfully', a) the actual frequencies have now changed and b) licenced frequencies in the 211 - 217MHz band have moved, since DAB have taken those.