[xk] Horns

The concourse judge told me that I should have had two horns sounding and
he could only hear one. Either a high or a low note was out of order. Is
there supposed to be two horns on a 1954 120 DHC?
Town and country or two horns blowing at the same time ? or just one horn
with dual trumpits?
E.W. Blake

Dear EWB: Two horns for the 120, the notes separated by a minor third
according to Lucas if I recall correctly. Regards, John Elmgreen

Was the concours judge by any chance named Joshua and does he hail from the
town of Jericho ?

No!
E.W.----------

From: Phil Maurice ijest@ihug.co.nz
To: xk@jag-lovers.org
Subject: Re: [xk] Horns
Date: Monday, August 03, 1998 1:38 AM

Was the concurs judge by any chance named Joshua and does he hail from
the
town of Jericho ?

Larry J, you say you got the correct tones for the horns: do you know the
interval between the notes is meant to be a minor third? That was a bit of
a “find” on a “dig” a while back! Regards, John Elmgreen

Question for musicians on the list:

I used my tuba tuner on the 120 horns and it indicates a D and a G. Is
that a “minor third”?–
A light-heeled mother maks a heavy-heeled daughter. (Scottish proverb)
Bruce Cunningham - http://www.together.net/~bcunning/
Slainte Mhath

Bill,
I don’t remember where I got them or how much I paid. I got them in
1968. J.C.Whitney pops into my head but I really don’t know. I was at
Whiteman AFB, Mo. at the time. They sound like a big semi but more musical.

Ted Zenuk
XK140MC FHC
Tucson, Az.

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto2011/5/22 Klaus Nielsen Klausnielsen@earthlink.net:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen <@KWN>:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

If anyone has a high and a low, it would interesting to note any
significant difference in the shapes of the spirals - especially the
lengths.

They are musical instruments and the frequency produced can be
influenced by the characteristics of the vibrating column of air rather
than (or in addition to) the trigger (vibrating diaphram)

Klaus,

On the HF 1748 series of horns the difference between the High and Low notes
is the diaphragm. The correct horns for an XK 140 are Lucas part no. 70063D
(low) and 70071D (High).

The only difference in the major parts is the part number of the diaphragm -
703726 (Low) and 703727 (High). You can hear the difference quite clearly if
you tap the tone disc. I have several horns for refurbishment but I have yet
to dismantle one. I suspect the tuning of the diaphragm is done with the
radial slots or maybe, the thickness. When I take one apart I’ll let you
know.

Eric
Church Stretton, UK----- Original Message -----
From: “Klaus Nielsen” Klausnielsen@earthlink.net
To: xk@jag-lovers.org
Sent: Sunday, May 22, 2011 5:15 AM
Subject: [xk] Horns

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
Klausnielsen@earthlink.net writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen Klausnielsen@earthlink.net:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Branching out to other interested sources, I found some information about
Lucas horns on a motorcycle list.

http://archives.jampot.dk/Technical/Electric/Lucas/Lucas_Service_Sheets/Lucas_Horns_HF1849.pdf
This Tiny URL may work better:
http://tinyurl.com/3mojcgm

In the second paragraph under “GENERAL” it discusses how the tone is
generated. Even though the leaflet is about a different model, it does show
how the Lucas mind works. I suspect some motorcycle stough uses 6V.
Allowing for that, I believe some of the tests given there are a good
starting point for ours.

On their website, if you go backwards using the “To Parent Directory” you
will see other Lucas equipment.

Gene McGough
XK-150 FHC S834515DN
XJ6C II 1976

Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one
but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
Klausnielsen@earthlink.net writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus

Alberto Taborcias
Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn�t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto----- Original Message -----
From: Ottman0401@aol.com
Sent: Sunday, May 22, 2011 12:24 PM
-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Sent: Sunday, May 22, 2011 10:33 AM

2011/5/22 Klaus Nielsen Klausnielsen@earthlink.net:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Bruce
1748s have no spirals.
Best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Bruce Cunningham
Sent: Sunday, May 22, 2011 11:05 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

If anyone has a high and a low, it would interesting to note any
significant difference in the shapes of the spirals - especially the
lengths.

They are musical instruments and the frequency produced can be
influenced by the characteristics of the vibrating column of air rather
than (or in addition to) the trigger (vibrating diaphram)

Gene

Thank you. It sounds like we have the start of a thread with some noise
attached.
Best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Gene McGough
Sent: Sunday, May 22, 2011 6:08 PM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Branching out to other interested sources, I found some information about
Lucas horns on a motorcycle list.

http://archives.jampot.dk/Technical/Electric/Lucas/Lucas_Service_Sheets/Luca
s_Horns_HF1849.pdf
This Tiny URL may work better:
http://tinyurl.com/3mojcgm

In the second paragraph under “GENERAL” it discusses how the tone is
generated. Even though the leaflet is about a different model, it does show

how the Lucas mind works. I suspect some motorcycle stough uses 6V.
Allowing for that, I believe some of the tests given there are a good
starting point for ours.

On their website, if you go backwards using the “To Parent Directory” you
will see other Lucas equipment.

Gene McGough
XK-150 FHC S834515DN
XJ6C II 1976

----- Original Message -----
From: Ottman0401@aol.com
Sent: Sunday, May 22, 2011 12:24 PM

Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one
but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
@KWN writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen <@KWN>:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Eric
Oh bother!!! I should have known that it is the part that is hardest to
duplicate, but with no parts list for the 1748, I could not tell.
So, now the hunt is on for a “Low” parts horn or just a correct diaphragm.
Many thanks.
Best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Eric Capron
Sent: Sunday, May 22, 2011 11:36 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Klaus,

On the HF 1748 series of horns the difference between the High and Low notes

is the diaphragm. The correct horns for an XK 140 are Lucas part no. 70063D
(low) and 70071D (High).

The only difference in the major parts is the part number of the diaphragm -

703726 (Low) and 703727 (High). You can hear the difference quite clearly if

you tap the tone disc. I have several horns for refurbishment but I have yet

to dismantle one. I suspect the tuning of the diaphragm is done with the
radial slots or maybe, the thickness. When I take one apart I’ll let you
know.

Eric
Church Stretton, UK
----- Original Message -----
From: “Klaus Nielsen” <@KWN>
To: xk@jag-lovers.org
Sent: Sunday, May 22, 2011 5:15 AM
Subject: [xk] Horns

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Hello Otto
Yes, it has been too long and I’ll come down soon. Thank you for the
reference to the horns. Needless to say, all of mine are of the old style
dated between '52 and '56. I just wish he had included a photo of the “Low”
diaphragm for comparison with my four “High” samples. I still do not know if
it is only the thickness that differs between the two.
Best
Klaus-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Ottman0401@aol.com
Sent: Sunday, May 22, 2011 2:25 PM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one
but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
@KWN writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen <@KWN>:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Klaus,
My horns are both marked HF 1748. One has a Lucas number 70063E, the other
70071E. 1957.
Both disks measure the same thickness and approx diameter because they are
not perfectly round. Not on purpose, just not finished.

Both disks ring like a bell when tapped, both at the same frequency.

I haven’t been able to get them further apart, having broken two screws so
far.

Gene McGough
XK-150 FHC S834515DN
XJ6C II 1976----- Original Message -----
From: “Klaus Nielsen” Klausnielsen@earthlink.net
Sent: Sunday, May 22, 2011 9:37 PM

Hello Otto
Yes, it has been too long and I’ll come down soon. Thank you for the
reference to the horns. Needless to say, all of mine are of the old style
dated between '52 and '56. I just wish he had included a photo of the “Low”
diaphragm for comparison with my four “High” samples. I still do not know if
it is only the thickness that differs between the two.
Best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Ottman0401@aol.com
Sent: Sunday, May 22, 2011 2:25 PM
Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one
but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
Klausnielsen@earthlink.net writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn�t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen Klausnielsen@earthlink.net:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW

Hello Gentleman,

Yes, no spirals in this horn model…
My 150 Klaus is not finished - interior, soft top and paint issues -
but driving perfect…
Best regards to all of you

Alberto2011/5/23 Gene McGough genemc@cavemen.net:

Klaus,
My horns are both marked HF 1748. One has a Lucas number 70063E, the other
70071E. 1957.
Both disks measure the same thickness and approx diameter because they are
not perfectly round. Not on purpose, just not finished.

Both disks ring like a bell when tapped, both at the same frequency.

I haven’t been able to get them further apart, having broken two screws so
far.

Gene McGough
XK-150 FHC S834515DN
XJ6C II 1976

----- Original Message ----- From: “Klaus Nielsen”
Klausnielsen@earthlink.net
Sent: Sunday, May 22, 2011 9:37 PM

Hello Otto
Yes, it has been too long and I’ll come down soon. Thank you for the
reference to the horns. Needless to say, all of mine are of the old style
dated between '52 and '56. I just wish he had included a photo of the “Low”
diaphragm for comparison with my four “High” samples. I still do not know if
it is only the thickness that differs between the two.
Best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Ottman0401@aol.com
Sent: Sunday, May 22, 2011 2:25 PM
Hi Klaus,
How’s it going with you, haven’t seen you in a while, good to see you back
here.
Here’s a link’ posted to the album by Robert???, of the guts of the low
tone horn. Same number that Eric mentioned, 70063, maybe you can get some
info from there. I have one of the horns apart, don’t remember which one
but I
can measure the disk to see if there is a difference in the thickness.

http://www.jag-lovers.org/snaps/snap_view.php3?id=1273134689&n4=

Regards, Otto M.

In a message dated 5/22/2011 10:54 Eastern Daylight Time,
Klausnielsen@earthlink.net writes:
Hi Alberto
Thanks for your reply.
In the search for correct replacement horns for the current aftermarket
horns in my OTS, I have ended up with two NOS and two basket case 1748
horns, all of which have the small identifying tag showing them to be Hi
tone units.
I asked the listers if anyone knows what makes these either high or low
frequency horns, because, if it is only the mass/weight of the front disc
that sets the frequency, it would be a trivial matter to machine a heavier
disc.
Hope I get a bite!

How is your car running?
All the best
Klaus

-----Original Message-----
From: owner-xk@jag-lovers.org [mailto:owner-xk@jag-lovers.org] On Behalf Of
Alberto Taborcias
Sent: Sunday, May 22, 2011 10:33 AM
To: xk@jag-lovers.org
Subject: Re: [xk] Horns

Hello Klaus,

Remember when Rick and you set an special operation to help me
answering some doubts I had to fix one of my horns…

Now I have no access to the horns inners (sorry), but what my memory
tell me, when I was there didn´t see any evident physical difference
between both the hi and the low tone, neither out or inside. Could be
lack of subtle perception.
Only the ID on the back tag; and the sound of course.
I wonder if it can be a matter of different coil or shunt
configuration, that delivers different frequencies.

Are you sure those you have are all hi tone? Have you try them?
Both mine showed ALTO ( means HI ) in the upper front, but the sounds
are hi and lo…
Repeat, there should be a metal tag on the back with different ID for
both tones.

Best regards,

Alberto

2011/5/22 Klaus Nielsen Klausnielsen@earthlink.net:

Listers

On the two Lucas 1748 horns on the 140 models, what internal components
differ to generate respectively the high and the low tones.
I assume, it is be done by either changing the spring constant of the
diaphragm or the mass of the front disc, but as I at present only have
Hi-tones at hand, I cannot tell.

Might anybody out there have the answer?

Best

Klaus W. Nielsen

812394
815666BW