The Mellotron Group

On Fri, Feb 24, 2012 at 2:45 PM, tron400 <tron400@yahoo.com> wrote:

#500 has had an intermittant hum for a while now. I thought that maybe it was related to the volume pedal jack, but I noticed yesterday that the volume of the hum changes when I move the track selector. Track C doesn't seem to have any hum, but Tracks A and B do. Any idea what the cause might be?

Bernie

--

john barrick

*Leo got it right the first time*

*then he added a second pickup and got it righter*

On Fri, Feb 24, 2012 at 2:53 PM, john barrick <barrickjohn262@gmail.com> wrote:

Maybe the cable going from the head block to the preamp?

On Fri, Feb 24, 2012 at 2:45 PM, tron400 <tron400@yahoo.com> wrote:

#500 has had an intermittant hum for a while now. I thought that maybe it was related to the volume pedal jack, but I noticed yesterday that the volume of the hum changes when I move the track selector. Track C doesn't seem to have any hum, but Tracks A and B do. Any idea what the cause might be?

Bernie
-

john barrick

*Leo got it right the first time*

*then he added a second pickup and got it righter*

#500 has had an intermittant hum for a while now. I thought that maybe it was related to the volume pedal jack, but I noticed yesterday that the volume of the hum changes when I move the track selector. Track C doesn't seem to have any hum, but Tracks A and B do. Any idea what the cause might be?

Bernie

--- In newmellotrongroup@yahoogroups.com, lsf5275@... wrote:
>
> Good call Bruce... I didn't see your post or I wouldn't have repeated the
> information.
>
> Frank
>
>
> In a message dated 2/25/2012 1:30:16 A.M. Eastern Standard Time,
> pocotron@... writes:
>
>
>
>
>
> Hey Bernie-
> The headblock must remain electrically isolated from the chassis to
> avoid this.
> Last time this happened to me I had a missing headblock roller (previous
> owner's fault, which I fixed). Therefore, the headblock was rubbing the
> chassis, which changed the hum when different tracks were selected. A bad
> cable can also cause this problem, but it is usually screechy(not good for
> tapes). Check the w-clips that hold down the headblock, their centering
> washers may be off-set or worn through, and may be causing the short. You may
> have to remove the headblock to fix this one.
> The track selector mechanism can also cause this short. However, if
> this is the machine that Jerry Korb refurbished, he probably already fixed
> this.
>
> Hope this helps, best of luck. More sugar!
>
> -Bruce Daily
>
>
>
>
>
>
>
> From: john barrick <barrickjohn262@...>
> To: newmellotrongroup@yahoogroups.com
> Sent: Friday, February 24, 2012 1:55 PM
> Subject: Re: [newmellotrongroup] Grounding Issue?
>
>
>
>
>
> Try putting it in the C position and then wiggle the cable a bit while
> playing a note. That may reproduce it.
>
> On Fri, Feb 24, 2012 at 2:53 PM, john barrick <_barrickjohn262@..._
> (mailto:barrickjohn262@...) > wrote:
>
> Maybe the cable going from the head block to the preamp?
>
>
>
> On Fri, Feb 24, 2012 at 2:45 PM, tron400 <_tron400@..._
> (mailto:tron400@...) > wrote:
>
>
>
>
>
> #500 has had an intermittant hum for a while now. I thought that maybe it
> was related to the volume pedal jack, but I noticed yesterday that the
> volume of the hum changes when I move the track selector. Track C doesn't seem
> to have any hum, but Tracks A and B do. Any idea what the cause might be?
>
> Bernie
> -
>
>
>
>
>
>
>
>
>
>
> john barrick
>
>
> *Leo got it right the first time*
> *then he added a second pickup and got it righter*
>

--- In newmellotrongroup@yahoogroups.com, "tron400" <tron400@...> wrote:
>
> Wouldn't you know, it's not acting up at the moment. I'll have to leave it running for a while.
>
> Jerry put a new cable in when he refurbished it. The old one had the screeching cable rot.
>
> BTW, anyone have an empty frame laying around?
>
> Bernie
>
> --- In newmellotrongroup@yahoogroups.com, lsf5275@ wrote:
> >
> > Good call Bruce... I didn't see your post or I wouldn't have repeated the
> > information.
> >
> > Frank
> >
> >
> > In a message dated 2/25/2012 1:30:16 A.M. Eastern Standard Time,
> > pocotron@ writes:
> >
> >
> >
> >
> >
> > Hey Bernie-
> > The headblock must remain electrically isolated from the chassis to
> > avoid this.
> > Last time this happened to me I had a missing headblock roller (previous
> > owner's fault, which I fixed). Therefore, the headblock was rubbing the
> > chassis, which changed the hum when different tracks were selected. A bad
> > cable can also cause this problem, but it is usually screechy(not good for
> > tapes). Check the w-clips that hold down the headblock, their centering
> > washers may be off-set or worn through, and may be causing the short. You may
> > have to remove the headblock to fix this one.
> > The track selector mechanism can also cause this short. However, if
> > this is the machine that Jerry Korb refurbished, he probably already fixed
> > this.
> >
> > Hope this helps, best of luck. More sugar!
> >
> > -Bruce Daily
> >
> >
> >
> >
> >
> >
> >
> > From: john barrick <barrickjohn262@>
> > To: newmellotrongroup@yahoogroups.com
> > Sent: Friday, February 24, 2012 1:55 PM
> > Subject: Re: [newmellotrongroup] Grounding Issue?
> >
> >
> >
> >
> >
> > Try putting it in the C position and then wiggle the cable a bit while
> > playing a note. That may reproduce it.
> >
> > On Fri, Feb 24, 2012 at 2:53 PM, john barrick <_barrickjohn262@_
> > (mailto:barrickjohn262@) > wrote:
> >
> > Maybe the cable going from the head block to the preamp?
> >
> >
> >
> > On Fri, Feb 24, 2012 at 2:45 PM, tron400 <_tron400@_
> > (mailto:tron400@) > wrote:
> >
> >
> >
> >
> >
> > #500 has had an intermittant hum for a while now. I thought that maybe it
> > was related to the volume pedal jack, but I noticed yesterday that the
> > volume of the hum changes when I move the track selector. Track C doesn't seem
> > to have any hum, but Tracks A and B do. Any idea what the cause might be?
> >
> > Bernie
> > -
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > john barrick
> >
> >
> > *Leo got it right the first time*
> > *then he added a second pickup and got it righter*
> >
>

Looks like it was one of the spring hooks that holds the head block in place. One of them was not in its hole.

Bernie

--- In newmellotrongroup@yahoogroups.com, "tron400" <tron400@...> wrote:
>
> Wouldn't you know, it's not acting up at the moment. I'll have to leave it running for a while.
>
> Jerry put a new cable in when he refurbished it. The old one had the screeching cable rot.
>
> BTW, anyone have an empty frame laying around?
>
> Bernie
>
> --- In newmellotrongroup@yahoogroups.com, lsf5275@ wrote:
> >
> > Good call Bruce... I didn't see your post or I wouldn't have repeated the
> > information.
> >
> > Frank
> >
> >
> > In a message dated 2/25/2012 1:30:16 A.M. Eastern Standard Time,
> > pocotron@ writes:
> >
> >
> >
> >
> >
> > Hey Bernie-
> > The headblock must remain electrically isolated from the chassis to
> > avoid this.
> > Last time this happened to me I had a missing headblock roller (previous
> > owner's fault, which I fixed). Therefore, the headblock was rubbing the
> > chassis, which changed the hum when different tracks were selected. A bad
> > cable can also cause this problem, but it is usually screechy(not good for
> > tapes). Check the w-clips that hold down the headblock, their centering
> > washers may be off-set or worn through, and may be causing the short. You may
> > have to remove the headblock to fix this one.
> > The track selector mechanism can also cause this short. However, if
> > this is the machine that Jerry Korb refurbished, he probably already fixed
> > this.
> >
> > Hope this helps, best of luck. More sugar!
> >
> > -Bruce Daily
> >
> >
> >
> >
> >
> >
> >
> > From: john barrick <barrickjohn262@>
> > To: newmellotrongroup@yahoogroups.com
> > Sent: Friday, February 24, 2012 1:55 PM
> > Subject: Re: [newmellotrongroup] Grounding Issue?
> >
> >
> >
> >
> >
> > Try putting it in the C position and then wiggle the cable a bit while
> > playing a note. That may reproduce it.
> >
> > On Fri, Feb 24, 2012 at 2:53 PM, john barrick <_barrickjohn262@_
> > (mailto:barrickjohn262@) > wrote:
> >
> > Maybe the cable going from the head block to the preamp?
> >
> >
> >
> > On Fri, Feb 24, 2012 at 2:45 PM, tron400 <_tron400@_
> > (mailto:tron400@) > wrote:
> >
> >
> >
> >
> >
> > #500 has had an intermittant hum for a while now. I thought that maybe it
> > was related to the volume pedal jack, but I noticed yesterday that the
> > volume of the hum changes when I move the track selector. Track C doesn't seem
> > to have any hum, but Tracks A and B do. Any idea what the cause might be?
> >
> > Bernie
> > -
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > john barrick
> >
> >
> > *Leo got it right the first time*
> > *then he added a second pickup and got it righter*
> >
>

On 2/26/12, lsf5275@aol.com <lsf5275@aol.com> wrote:
> With Mellotrons, as with Harley Davidsons, start with the simplest
> possibility and work your way up. Most of the problems are resolved at
> 'simple."
> Glad you found and fixed it.
>
> Frank
>
>
> In a message dated 2/25/2012 7:34:31 P.M. Eastern Standard Time,
> tron400@yahoo.com writes:
>
>
>
>
> Looks like it was one of the spring hooks that holds the head block in
> place. One of them was not in its hole.
>
> Bernie
>
> --- In _newmellotrongroup@yahoogroups.com_
> (mailto:newmellotrongroup@yahoogroups.com) , "tron400" <tron400@...> wrote:
>>
>> Wouldn't you know, it's not acting up at the moment. I'll have to leave
> it running for a while.
>>
>> Jerry put a new cable in when he refurbished it. The old one had the
> screeching cable rot.
>>
>> BTW, anyone have an empty frame laying around?
>>
>> Bernie
>>
>> --- In _newmellotrongroup@yahoogroups.com_
> (mailto:newmellotrongroup@yahoogroups.com) , lsf5275@ wrote:
>> >
>> > Good call Bruce... I didn't see your post or I wouldn't have repeated
> the
>> > information.
>> >
>> > Frank
>> >
>> >
>> > In a message dated 2/25/2012 1:30:16 A.M. Eastern Standard Time,
>> > pocotron@ writes:
>> >
>> >
>> >
>> >
>> >
>> > Hey Bernie-
>> > The headblock must remain electrically isolated from the chassis to
>> > avoid this.
>> > Last time this happened to me I had a missing headblock roller
> (previous
>> > owner's fault, which I fixed). Therefore, the headblock was rubbing
> the
>> > chassis, which changed the hum when different tracks were selected. A
> bad
>> > cable can also cause this problem, but it is usually screechy(not good
> for
>> > tapes). Check the w-clips that hold down the headblock, their
> centering
>> > washers may be off-set or worn through, and may be causing the short.
> You may
>> > have to remove the headblock to fix this one.
>> > The track selector mechanism can also cause this short. However, if
>> > this is the machine that Jerry Korb refurbished, he probably already
> fixed
>> > this.
>> >
>> > Hope this helps, best of luck. More sugar!
>> >
>> > -Bruce Daily
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > From: john barrick <barrickjohn262@>
>> > To: _newmellotrongroup@yahoogroups.com_
> (mailto:newmellotrongroup@yahoogroups.com)
>> > Sent: Friday, February 24, 2012 1:55 PM
>> > Subject: Re: [newmellotrongroup] Grounding Issue?
>> >
>> >
>> >
>> >
>> >
>> > Try putting it in the C position and then wiggle the cable a bit while
>> > playing a note. That may reproduce it.
>> >
>> > On Fri, Feb 24, 2012 at 2:53 PM, john barrick <_barrickjohn262@_
>> > (mailto:barrickjohn262@) > wrote:
>> >
>> > Maybe the cable going from the head block to the preamp?
>> >
>> >
>> >
>> > On Fri, Feb 24, 2012 at 2:45 PM, tron400 <_tron400@_
>> > (mailto:tron400@) > wrote:
>> >
>> >
>> >
>> >
>> >
>> > #500 has had an intermittant hum for a while now. I thought that maybe
> it
>> > was related to the volume pedal jack, but I noticed yesterday that the
>> > volume of the hum changes when I move the track selector. Track C
> doesn't seem
>> > to have any hum, but Tracks A and B do. Any idea what the cause might
> be?
>> >
>> > Bernie
>> > -
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > john barrick
>> >
>> >
>> > *Leo got it right the first time*
>> > *then he added a second pickup and got it righter*
>> >
>>
>
>
>
>
>

--- In newmellotrongroup@yahoogroups.com, lsf5275@... wrote:
>
> Actually, you led him to this one.
>
> In a message dated 2/26/2012 1:55:59 A.M. Eastern Standard Time,
> pocotron@... writes:
>
>
>
>
>
> Frank-
> You taught us well, Obi-Wan, thank you! Looks like Bernie found it.
>
> -Bruce D.
>
>
>
>
>
>
>
> From: "lsf5275@..." <lsf5275@...>
> To: newmellotrongroup@yahoogroups.com
> Sent: Saturday, February 25, 2012 12:04 AM
> Subject: Re: [newmellotrongroup] Grounding Issue?
>
>
>
>
>
>
> Good call Bruce... I didn't see your post or I wouldn't have repeated the
> information.
>
> Frank
>
>
> In a message dated 2/25/2012 1:30:16 A.M. Eastern Standard Time,
> pocotron@... writes:
>
>
>
>
> Hey Bernie-
> The headblock must remain electrically isolated from the chassis to
> avoid this.
> Last time this happened to me I had a missing headblock roller (previous
> owner's fault, which I fixed). Therefore, the headblock was rubbing the
> chassis, which changed the hum when different tracks were selected. A bad
> cable can also cause this problem, but it is usually screechy(not good for
> tapes). Check the w-clips that hold down the headblock, their centering
> washers may be off-set or worn through, and may be causing the short. You may
> have to remove the headblock to fix this one.
> The track selector mechanism can also cause this short. However, if
> this is the machine that Jerry Korb refurbished, he probably already fixed
> this.
>
> Hope this helps, best of luck. More sugar!
>
> -Bruce Daily
>
>
>
>
>
>
>
> From: john barrick <barrickjohn262@...>
> To: newmellotrongroup@yahoogroups.com
> Sent: Friday, February 24, 2012 1:55 PM
> Subject: Re: [newmellotrongroup] Grounding Issue?
>
>
>
>
>
> Try putting it in the C position and then wiggle the cable a bit while
> playing a note. That may reproduce it.
>
> On Fri, Feb 24, 2012 at 2:53 PM, john barrick <_barrickjohn262@..._
> (mailto:barrickjohn262@...) > wrote:
>
> Maybe the cable going from the head block to the preamp?
>
>
>
> On Fri, Feb 24, 2012 at 2:45 PM, tron400 <_tron400@..._
> (mailto:tron400@...) > wrote:
>
>
>
>
>
> #500 has had an intermittant hum for a while now. I thought that maybe it
> was related to the volume pedal jack, but I noticed yesterday that the
> volume of the hum changes when I move the track selector. Track C doesn't seem
> to have any hum, but Tracks A and B do. Any idea what the cause might be?
>
> Bernie
> -
>
>
>
>
>
>
>
>
>
>
> john barrick
>
>
> *Leo got it right the first time*
> *then he added a second pickup and got it righter*
>