Sennheiser MKH-5 BPIUP power unit info

[Bruce Hatch]

Have you heard of Sennheiser MKH-5 BPIUP power unit? It is a belt pack power pack but I do not know if it is a "T" supply or something else. Runs on 2-9vdc batteries and has a three position switch off/high/norm. A schematic would be wonderful since someone tried to "repair" this one.

[Hugh Robjohns]

Have you heard of Sennheiser MKH-5 BPIUP power unit?

It's not a number I recognise, but sennheiser made various bnattery units that supplied phantom or T power, usually with switchable high-pass filters and/or pads included.

John Willet (who posts here regularly) was Sennheiser UK's technical manager and will definitely know more...

H

[John Willett]

Have you heard of Sennheiser MKH-5 BPIUP power unit? It is a belt pack power pack but I do not know if it is a "T" supply or something else. Runs on 2-9vdc batteries and has a three position switch off/high/norm. A schematic would be wonderful since someone tried to "repair" this one.

If this is what I think it is - it's 30 or 40 years old.

I *think* that the MKH 5 was an RF condenser tie microphone - this was discontinued before I joined Sennheiser in 1985 (I left in 2010 and now distribute Microtech Gefell), though I think I have an old 1977 "Sennheiser Revue" in the loft somewhere with a picture and spec. of it - but it will take some finding.

The prefix "MKH" was only used for an RF condenser mic. and *never* for an accessory.

An accessory would normally be prefixed "MZA".

I think what yo have is the belt pack that went with the MKH 5 tie mic. and is not usable with any other product.

NB: I am not absolutely sure of this and may have to do a bit more research.

[John Willett]

OK - you had me intrigued - so I went searching in the loft for my old "Sennheiser Revue 8" from the mid 1970's.

The microphone I was thinking of is not an MKH 5 - but an MKH 124 or MKH 125.

I have scanned the data pages on these microphones and also of the power supplies from the same era, see below.







I think, to get to the root of your problem, I will need to see a photo, or photos.

John

[Bruce Hatch]

As far as I have proceeded, it looks as if this is the predecessor to the BP 2. The MKH --5 is evidently to indicate that it is a Belt Pack "T power" unit for the MKH xx5 (105,405& 805) units.
In order to repair this one I need to find an ALCOSWITCH MRA-3-3 does anyone have any leads?
I will try to post pics. How do I post them?
Bruce

[zenguitar]

To post a photo here you need to upload it to an online hosting service like Flikr or Photobucket. Once you have it online you can use the Instant UBB Code button to insert it as a link and the forum software will display it. Although the software should resize the image to fit, we do recommend that you save it online with the longest side at 800 pixels.

Hope that helps,

Andy

[John Willett]

As far as I have proceeded, it looks as if this is the predecessor to the BP 2. The MKH --5 is evidently to indicate that it is a Belt Pack "T power" unit for the MKH xx5 (105,405& 805) units.
In order to repair this one I need to find an ALCOSWITCH MRA-3-3 does anyone have any leads?
I will try to post pics. How do I post them?
Bruce

Have you asked Sennheiser?

They often have historic spare parts available.

If there is a service manual available it will be on-line on the special Sennheiser website that is only accessible to Sennheiser and their agents - but they can download this as a PDF and e-mail it to you.