Leitz Focomat v35 buzzing
 

My enlarger head makes a buzzing sound whenever the light's on and the
enlargement intensity fluctuates slightly. It's still useable, but
every so often a print is a little lighter or darker than expected.
I've ascertained the problem isn't in the timer unit, and the bulb is
new, so what could it be? Has anybody else had this problem? Thanks...

Leitz Focomat v35 buzzing
 

"Bendzh" wrote

[Leitz V35] head makes a buzzing sound whenever the light's on and the
enlargement intensity fluctuates slightly.

If you are sure the buzzing is in the head the most likely cause
is a loose connection. Usually:

hissing buzz = loose connection, arcing
rattling buzz = loose transformer core, relay or hardware
humming buzz = loose transformer coil

Is the buzz constant? Happen all the time? What happens
if you give the enlarger a slap [like an old TV set]?

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.nolindan.com/da/index.htm
n o lindan at ix dot netcom dot com

Leitz Focomat v35 buzzing
 

"Nicholas O. Lindan" wrote in message
ink.net...
"Bendzh" wrote

[Leitz V35] head makes a buzzing sound whenever the
light's on and the
enlargement intensity fluctuates slightly.

If you are sure the buzzing is in the head the most likely
cause
is a loose connection. Usually:

hissing buzz = loose connection, arcing
rattling buzz = loose transformer core, relay or hardware
humming buzz = loose transformer coil

Is the buzz constant? Happen all the time? What happens
if you give the enlarger a slap [like an old TV set]?

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.nolindan.com/da/index.htm
n o lindan at ix dot netcom dot com
Also check the lamp socket.


--
---
Richard Knoppow
Los Angeles, CA, USA




--
Posted via a free Usenet account from http://www.teranews.com

Leitz Focomat v35 buzzing
 

On Sat, 24 Feb 2007 16:02:07 -0800, "Richard Knoppow"
wrote:

Also check the lamp socket.


Indeed.

The screw-in clamp can loosen and has caused buzzing on both my V35s.

Leitz Focomat v35 buzzing
 

Slapping the head does nothing, and I have the lamp holder screwed in
tight. The buzzing's continuous but gets softer and louder as the bulb
is brighter and weaker.

Leitz Focomat v35 buzzing
 

I did think of the transformer, but wouldn't the sound be coming from
there rather than the head in that case? Or maybe the fluctuating
current induces buzzing in the head?

Leitz Focomat v35 buzzing
 

On 25 Feb 2007 11:50:21 -0800, "Bendzh"
wrote:
I did think of the transformer, but wouldn't the sound be coming from
there rather than the head in that case? Or maybe the fluctuating
current induces buzzing in the head?


The current to the bulb is 12V AC (alternating current) so it is
capable of causing buzzing at 50Hz.

Leitz Focomat v35 buzzing
 

"Bendzh" wrote in message
ups.com...
Slapping the head does nothing, and I have the lamp holder
screwed in
tight. The buzzing's continuous but gets softer and louder
as the bulb
is brighter and weaker.

Check the lamp itself and the condition of the contacts
in the holder. If the lamp socket or lamp base are corroded
they may have developed intermittant high resistance which
may also cause the buzzing. Of course, also check the
wiring.
A voltmeter will also be helpful in discovering if the
output of the transformer is varying around.
The source of the buzzing may be difficult to localize. A
makeshift stethescope will help. This can be no more than a
stick of wood or even a long pencil. Hold one end against
you ear and poke the other around where you think the sound
is coming from. Sometimes this will locate the source. Its
an old auto mechanic's trick.
It is possible for the lamp itself to be producing the
buzz. Lamps sometimes do this when near the end of their
lives. That might also account for the variation in
brightness.


--
---
Richard Knoppow
Los Angeles, CA, USA




--
Posted via a free Usenet account from http://www.teranews.com

Leitz Focomat v35 buzzing
 

On Sun, 25 Feb 2007 18:39:16 -0800, "Richard Knoppow"
wrote:

It is possible for the lamp itself to be producing the
buzz. Lamps sometimes do this when near the end of their
lives. That might also account for the variation in
brightness.


True.

To the OP:

If there is a variation in brightness, there will also be a
significant variation in colour temperature, which could significantly
affect results.

A new bulb may well effect a cure. Philips 13139, or 6604 if you have
the earlier bulb holder. The 6604 is hard to find and expensive.

Most Focomat V35 enlargers have been converted to take the later
Philips 13139 bulb, which is much easier to find and reasonably
priced, for example GBP 11.55 from:

http://www.bltdirect.com/products.ph...rent=7&cat=228

If you remove the protective plate over the rear of the enlarger head,
you will find the bulb type clearly marked.