It turns out that the entire tuning mechanism slips when the set is tapped or subjected to vibration. How can it be tightened up so it cannot slip so much? What areas should be looked at? Could a spring be weak? It looks as if the radio was dropped at one time. There was a dent made by the tuning shaft in the nose piece. That was pretty much hammered out. There is a thin brass disc at the other end of the tuning shaft near where the shaft's geared end meshes with the tuning gear. It was bent too. I straightened it out. Something else is probably bent preventing something else from exerting pressure somewhere so that the tuning mechanism cannot slip. But I don't know where that is.
Please help me find it.
Thanks,
Dave
If the set is tuned to a station and not tapped and there is no vibration, the radio continues playing that station until it's shut off or tuned to another station.
I guess nobody knows then. Should I send a picture?
Thanks,
Dave
:Hello All,
: It turns out that the entire tuning mechanism slips when the set is tapped or subjected to vibration. How can it be tightened up so it cannot slip so much? What areas should be looked at? Could a spring be weak? It looks as if the radio was dropped at one time. There was a dent made by the tuning shaft in the nose piece. That was pretty much hammered out. There is a thin brass disc at the other end of the tuning shaft near where the shaft's geared end meshes with the tuning gear. It was bent too. I straightened it out. Something else is probably bent preventing something else from exerting pressure somewhere so that the tuning mechanism cannot slip. But I don't know where that is.
:
:Please help me find it.
:
:Thanks,
:
:Dave
:
:If the set is tuned to a station and not tapped and there is no vibration, the radio continues playing that station until it's shut off or tuned to another station.
Sir Dave:
Buy you books.....send you to school......teach you ALL that we know....and you STILL
have problems fixing them thar'
'ole ray-dee-oos........(now engaging tongue in cheek.....pausing.....ROTFLOL)
Thank goodness that I am initially composing this via voice recognition and it will then only need
its final proofing and editing.
I am placing a visual referencing just below this line, since it will probably need to be cross
referenced frequently...its J-pegged...so mag it on up for max resolution !
Initially lets notice that the sets basic variable tuning mechanism is enclosed within a metal
cased framework as designated by arrow A.
Mounted within that infrastructure you will see three
grommets, as referenced by arrows G . They are supporting / mounting the bottom ends of the sets
RF-mixer-osc coils. Their manner of accomplishing tuning is by the varying of their inductance. In the
photo, you can see their individual ferrite cores up at their top protruding portions (being identified by
red squares).
Protruding fron that top side of the cores are internally imbedded fine threaded brass rods (or STIFF
brass wire coils, forming fine wound closed mini-loops, that functon as threads...on some
manufacturers utilized techniques ). That then permits their being threaded into their individual
plastic inserts,
just above them, which are mounted within the common metal tuning bar assembly (Ref arrow B). The
whole tuning bar assembly accomplishes intra-station tuning by moving in a straight linear
motion,front to back , in the direction shown by arrow B. That whole tuning bar / plate is riding within
linear slotted channels formed within housing A. Any undesired up and down play in that movable plate
is solved by the clock spring type of tensioning device shown at H. Just below the red arrow point,
one sees the rivet that mounts the spring, the spring comes down to the point where you can see it in
the viewing hole and the spring is then formed into a 1/2 turn loop, such that the length of the spring
then runs upwardly and remains parallel to the body of the tuning plate up to the point just above the
tip of the red arrow where a downward formed dimple can be seen formed into the end of that springs
end. This is the sliding/lubed pressure point that keeps any up and down movement of the plate in
check, yet with the whole plate being able to move freely in its front to back axis for accomplishing
tuning.
As far as the units manner of performing tuning; as that plate moves towards the back of the radio,
the slugs increase the coils inductance thereby tuning towards 540 Khz....in the opposing action of
extracting the slugs from within the coils, therewith, tuning towards 1740 Khz is accomplished. If the
separate adjustment of an individual coil is required for optimizing of RF tracking, or low band osc
alignment , that can be accomplished by the adjustment of the threaded brass rod at the top of the
slug with a special tool (or brute rotary force using needle nose pliers for slow turning) or some
manufacturers have the end of the ferrite slug having a centered slot cut
across it, such that an inserted plastic/fiberglass/nylon std screwdrivers tip can then rotate the slug.
That pretty well now covers the aspects of the electromechanical tuning being accomplished within
that assembly.
Now only two conjunct, yet separate, mechanical aspects are left to be examined in their manner
of operation.
Look at the bottom left of the drawing and note the vert green arrow; at its tip is a 1/4 in diameter
steel shaft that enters into the tuning compartment and engages into gearing such that its rotation
evolves into the linear movement of the internal tuning plate for the manual tuning in of the radio for
receiving stations. Examine the square ended portion of the hoz green arrow and you will see a brass
colored ring gear that is engaged into a pinion gear at reference arrow B. That is then going on
upwards to the manual tuning shaft and its outside tuning knob.
A basic explanation of the pushbutton tuning aspect of the unit may best be served by describing
the rudimentary technique used on the very oldest units from the 40-50's. On those units, they were
using round pushbutons on the front that went internally and each pushbutton would engage into and
rotate a threaded shaft such that its very end would engage into a threaded plate. That plate would
rest up against a rod that went across the front of that tuning plate. In that manner, you had
established a repeatable precise mechanical positioning of that tuning plate each time that particular
pushbutton was pressed in and it bottomed out to that pretuned positioning. The same condition was
then being established with each other pushbutton, and their required mechanical positioning for
tuning in their pre-selected stations
The next developmental upgrading was an internal
mechanical structuring mod such that one pulled out on the pushbutton and then the desired station
was manually tuned in and the pressing in of the pushbutton then locked in the aforementioned
mechanical positioning such that it was mechanically repeatable in its precise positioning as that
particular pushbutton was pressed. The next upgrade
being the aesthetic utilization of rectangular plastic pushbuttons, with the internal mechanical aspects
being the same.
Now one is up against the use of either tuning mechanism, with the conventional tuning of the
stations with the use of the frontal tuning knob and its being geared into producing the movement of
the tuning plate. BUT if one wanted to press in on a pushbutton in order to to swish immediately to a
predetermined mechanical positioning to get that station tuned in. All of that simultaneously engaged
low-geared string
mechanics would make the movement of that tuning plate impossible. That would require a complete
disassociation and non engagement of the manual tuning mechanics during the utilization of
pushbutton tuning. In order to understand how that is done, lets go back and review the construction
of the area associated with references C-D-E-F and the two mark up green reference arrows. There
is a transverse bar inside the tuning cage that starts engaging at the
very onset of the movement of any pushbutton. It is internally linked and exits out to be the arm shown
at ref D. Note that its top end is nestled in a groove inside the collar that is co-joined to the ring gear
shown to its left.That large collar also extends to the left and has two other components mechanically
swage mounted into it. These stand out better when viewing the bottom portion of the view.There is a
large disc/washer (its about 1/3 back from the tip of the green hoz arrow) made of the same spring
metal as was mentioned back at H reference. (Some manufacturers used... brassy looking... tensilized
phospor bronze) Note that its top portion is functioning in the keeping of a slight pressure on the
pinion gear and maintaining its engagement into the ring gear, irregardless of its rotational
positioning. Look now at the very tip of the hoz green arrow where you will see last thing that is
mounted onto the very end of that collar that we have been examining.It is a thicker metal disk that
has an altered profile, if you
will look again at the bottom of it and then compare it to the black mechanical referencing profile
placed aside at the left of the page. Its inwardly concave profile should then be more discernible when
you review the bottom of its photo. This offsetting permits the bonding of a large outer diameter
(large inner diameter concentric hole within it) rubber washer on the outer periphery as is shown with
black markup on the graphic. That serves as a clutch facing on that disc. This constitutes the four
aspects of the construction
of that sliding collar which all rides concentrically about that 1/4 ion tuning shaft riding through its
center core. Initially, there is the groove to the extreme right that had the lever at ref D engaging into
it, next is the spring disc that keeps the gears nestled, then the end disc with its clutch facing. This
whole cluster is capable of sliding laterally in response to the lever positioning at ref position
D.
The last consideration is the solid metal disk that is at the arrow tip of ref C. That plate is affixed to the
end
of the 1/4 shaft that is initially shown exiting at the vertical green reference arrow. On first generaton
radios that 1/4 in shaft was extending totally through disk C and on outwards a bit to the left of ref C
and there was an additional collar centered and mounted to the left of disk C such that an internal set
screw would let one shift its disk C's lateral positioning to set the pressure exerted into the
companion clutch disk that rests beside it. In this radios case, the lateral final positioning is provided
by lever D resting into the slot at the front of that clusters collar at marked up reference D. That
establishes clutch
pressure.
Now lets see how a station selection by pushbutton would be done. Initially, upon the engaging of
a pushbutton, the transverse bar that all of the pushbuttons are tied intowould detect that initial
pressure and convey it as a mechanical moment of lever D, that lever in the slot causes all of the
mechanics tied into that concentrically movable collar to shift to the right. The desired effect is to
have that clutch plate..... that is normally engaged into the end disk.... move away from that disk about
the spacing of a playing card. That then leaves the tuning plate totally freed from the manual tuning
mechanism and can zip right to its prescribed mechanical position to tune in that particular station.
Just as soon as the pushbutton is released, the movable collar snaps right back to its tensioned
manual positioning. This tensioning also is responsible for locking down front to back linear play in
the tuning plates
mechanism.
All of this info up to now is getting down to the final thought that just might be your problem, you
mentioned
a mechanical abnormality in the units tuning system. With a grasp now of the units basic operation,
check to see
if the clutch plate facing that engages into C is oil and grease FREE and grips well. Next press in a
pushbutton and confirm that the separation gap that is created to disk C is no more than a playing
cards thickness. Thus, assuring that your manual tuning is fully engaging after the release of a
pushbutton's selection. Otherwise, that
could leave the tuning plate with enough free play to mechanically shift its tuning when subjected to a
jar or vibration.
Additional observaton...note that this particular unit is using a universal joint at point F and just above
gear E there is a lateral slot in that mounting bracket to tolerate the shifting in those tuning mechanics
when that collared cluster is laterally shifted during a pushbuttons action.
Sorry for the solarization of some photo highlights, but I believe that enough detail was still captured
for viewing.
73's de Edd
:Hello Again,
: I guess nobody knows then. Should I send a picture?
:
:Thanks,
:
:Dave
::Hello All,
:: It turns out that the entire tuning mechanism slips when the set is tapped or subjected to vibration. How can it be tightened up so it cannot slip so much? What areas should be looked at? Could a spring be weak? It looks as if the radio was dropped at one time. There was a dent made by the tuning shaft in the nose piece. That was pretty much hammered out. There is a thin brass disc at the other end of the tuning shaft near where the shaft's geared end meshes with the tuning gear. It was bent too. I straightened it out. Something else is probably bent preventing something else from exerting pressure somewhere so that the tuning mechanism cannot slip. But I don't know where that is.
::
::Please help me find it.
::
::Thanks,
::
::Dave
::
::If the set is tuned to a station and not tapped and there is no vibration, the radio continues playing that station until it's shut off or tuned to another station.
Thanks very much. I made a copy of your post with the picture and will try to tighten up the mechanism.
Thanks,
Dave
:
:
:
:
:Sir Dave:
:
:Buy you books.....send you to school......teach you ALL that we know....and you STILL
:
:have problems fixing them thar'
: 'ole ray-dee-oos........(now engaging tongue in cheek.....pausing.....ROTFLOL)
:
:
:Thank goodness that I am initially composing this via voice recognition and it will then only need
:
:its final proofing and editing.
:
:
:I am placing a visual referencing just below this line, since it will probably need to be cross
:
:referenced frequently...its J-pegged...so mag it on up for max resolution !
:
:
:
:
:
:
:
:Initially lets notice that the sets basic variable tuning mechanism is enclosed within a metal
:
:cased framework as designated by arrow A.
: Mounted within that infrastructure you will see three
:
:grommets, as referenced by arrows G . They are supporting / mounting the bottom ends of the sets
:
:RF-mixer-osc coils. Their manner of accomplishing tuning is by the varying of their inductance. In the
:
:photo, you can see their individual ferrite cores up at their top protruding portions (being identified by
:
:red squares).
:
:Protruding fron that top side of the cores are internally imbedded fine threaded brass rods (or STIFF
:
:brass wire coils, forming fine wound closed mini-loops, that functon as threads...on some
:
:manufacturers utilized techniques ). That then permits their being threaded into their individual
:
:plastic inserts,
:just above them, which are mounted within the common metal tuning bar assembly (Ref arrow B). The
:
:whole tuning bar assembly accomplishes intra-station tuning by moving in a straight linear
:
:motion,front to back , in the direction shown by arrow B. That whole tuning bar / plate is riding within
:
:linear slotted channels formed within housing A. Any undesired up and down play in that movable plate
:
:is solved by the clock spring type of tensioning device shown at H. Just below the red arrow point,
:
:one sees the rivet that mounts the spring, the spring comes down to the point where you can see it in
:
:the viewing hole and the spring is then formed into a 1/2 turn loop, such that the length of the spring
:
:then runs upwardly and remains parallel to the body of the tuning plate up to the point just above the
:
:tip of the red arrow where a downward formed dimple can be seen formed into the end of that springs
:
:end. This is the sliding/lubed pressure point that keeps any up and down movement of the plate in
:
:check, yet with the whole plate being able to move freely in its front to back axis for accomplishing
:
:tuning.
:
:
:As far as the units manner of performing tuning; as that plate moves towards the back of the radio,
:
:the slugs increase the coils inductance thereby tuning towards 540 Khz....in the opposing action of
:
:extracting the slugs from within the coils, therewith, tuning towards 1740 Khz is accomplished. If the
:
:separate adjustment of an individual coil is required for optimizing of RF tracking, or low band osc
:
:alignment , that can be accomplished by the adjustment of the threaded brass rod at the top of the
:
:slug with a special tool (or brute rotary force using needle nose pliers for slow turning) or some
:
:manufacturers have the end of the ferrite slug having a centered slot cut
:across it, such that an inserted plastic/fiberglass/nylon std screwdrivers tip can then rotate the slug.
:
:That pretty well now covers the aspects of the electromechanical tuning being accomplished within
:
:that assembly.
:
:
:Now only two conjunct, yet separate, mechanical aspects are left to be examined in their manner
:
:of operation.
:
:
:Look at the bottom left of the drawing and note the vert green arrow; at its tip is a 1/4 in diameter
:
:steel shaft that enters into the tuning compartment and engages into gearing such that its rotation
:
:evolves into the linear movement of the internal tuning plate for the manual tuning in of the radio for
:
:receiving stations. Examine the square ended portion of the hoz green arrow and you will see a brass
:
:colored ring gear that is engaged into a pinion gear at reference arrow B. That is then going on
:
:upwards to the manual tuning shaft and its outside tuning knob.
:
:
:A basic explanation of the pushbutton tuning aspect of the unit may best be served by describing
:
:the rudimentary technique used on the very oldest units from the 40-50's. On those units, they were
:
:using round pushbutons on the front that went internally and each pushbutton would engage into and
:
:rotate a threaded shaft such that its very end would engage into a threaded plate. That plate would
:
:rest up against a rod that went across the front of that tuning plate. In that manner, you had
:
:established a repeatable precise mechanical positioning of that tuning plate each time that particular
:
:pushbutton was pressed in and it bottomed out to that pretuned positioning. The same condition was
:
:then being established with each other pushbutton, and their required mechanical positioning for
:
:tuning in their pre-selected stations
:The next developmental upgrading was an internal
:
:mechanical structuring mod such that one pulled out on the pushbutton and then the desired station
:
:was manually tuned in and the pressing in of the pushbutton then locked in the aforementioned
:
:mechanical positioning such that it was mechanically repeatable in its precise positioning as that
:
:particular pushbutton was pressed. The next upgrade
:being the aesthetic utilization of rectangular plastic pushbuttons, with the internal mechanical aspects
:
:being the same.
:
:
:Now one is up against the use of either tuning mechanism, with the conventional tuning of the
:
:stations with the use of the frontal tuning knob and its being geared into producing the movement of
:
:the tuning plate. BUT if one wanted to press in on a pushbutton in order to to swish immediately to a
:predetermined mechanical positioning to get that station tuned in. All of that simultaneously engaged
:
:low-geared string
:mechanics would make the movement of that tuning plate impossible. That would require a complete
:
:disassociation and non engagement of the manual tuning mechanics during the utilization of
:
:pushbutton tuning. In order to understand how that is done, lets go back and review the construction
:
:of the area associated with references C-D-E-F and the two mark up green reference arrows. There
:
:is a transverse bar inside the tuning cage that starts engaging at the
:very onset of the movement of any pushbutton. It is internally linked and exits out to be the arm shown
:
:at ref D. Note that its top end is nestled in a groove inside the collar that is co-joined to the ring gear
:
:shown to its left.That large collar also extends to the left and has two other components mechanically
:
:swage mounted into it. These stand out better when viewing the bottom portion of the view.There is a
:large disc/washer (its about 1/3 back from the tip of the green hoz arrow) made of the same spring
:
:metal as was mentioned back at H reference. (Some manufacturers used... brassy looking... tensilized
:
:phospor bronze) Note that its top portion is functioning in the keeping of a slight pressure on the
:
:pinion gear and maintaining its engagement into the ring gear, irregardless of its rotational
:
:positioning. Look now at the very tip of the hoz green arrow where you will see last thing that is
:
:mounted onto the very end of that collar that we have been examining.It is a thicker metal disk that
:
:has an altered profile, if you
:will look again at the bottom of it and then compare it to the black mechanical referencing profile
:
:placed aside at the left of the page. Its inwardly concave profile should then be more discernible when
:
:you review the bottom of its photo. This offsetting permits the bonding of a large outer diameter
:(large inner diameter concentric hole within it) rubber washer on the outer periphery as is shown with
:
:black markup on the graphic. That serves as a clutch facing on that disc. This constitutes the four
:
:aspects of the construction
:of that sliding collar which all rides concentrically about that 1/4 ion tuning shaft riding through its
:
:center core. Initially, there is the groove to the extreme right that had the lever at ref D engaging into
:
:it, next is the spring disc that keeps the gears nestled, then the end disc with its clutch facing. This
:
:whole cluster is capable of sliding laterally in response to the lever positioning at ref position
:
:D.
:
:
:The last consideration is the solid metal disk that is at the arrow tip of ref C. That plate is affixed to the
:
:end
:of the 1/4 shaft that is initially shown exiting at the vertical green reference arrow. On first generaton
:
:radios that 1/4 in shaft was extending totally through disk C and on outwards a bit to the left of ref C
:
:and there was an additional collar centered and mounted to the left of disk C such that an internal set
:
:screw would let one shift its disk C's lateral positioning to set the pressure exerted into the
:
:companion clutch disk that rests beside it. In this radios case, the lateral final positioning is provided
:
:by lever D resting into the slot at the front of that clusters collar at marked up reference D. That
:
:establishes clutch
:pressure.
:
:
:Now lets see how a station selection by pushbutton would be done. Initially, upon the engaging of
:
:a pushbutton, the transverse bar that all of the pushbuttons are tied intowould detect that initial
:
:pressure and convey it as a mechanical moment of lever D, that lever in the slot causes all of the
:mechanics tied into that concentrically movable collar to shift to the right. The desired effect is to
:
:have that clutch plate..... that is normally engaged into the end disk.... move away from that disk about
:
:the spacing of a playing card. That then leaves the tuning plate totally freed from the manual tuning
:
:mechanism and can zip right to its prescribed mechanical position to tune in that particular station.
:
:Just as soon as the pushbutton is released, the movable collar snaps right back to its tensioned
:manual positioning. This tensioning also is responsible for locking down front to back linear play in
:
:the tuning plates
:mechanism.
:
:
:
:All of this info up to now is getting down to the final thought that just might be your problem, you
:
:mentioned
:a mechanical abnormality in the units tuning system. With a grasp now of the units basic operation,
:
:check to see
:if the clutch plate facing that engages into C is oil and grease FREE and grips well. Next press in a
:
:pushbutton and confirm that the separation gap that is created to disk C is no more than a playing
:
:cards thickness. Thus, assuring that your manual tuning is fully engaging after the release of a
:
:pushbutton's selection. Otherwise, that
:could leave the tuning plate with enough free play to mechanically shift its tuning when subjected to a
:
:jar or vibration.
:
:Additional observaton...note that this particular unit is using a universal joint at point F and just above
:gear E there is a lateral slot in that mounting bracket to tolerate the shifting in those tuning mechanics
:when that collared cluster is laterally shifted during a pushbuttons action.
:
:
:Sorry for the solarization of some photo highlights, but I believe that enough detail was still captured
:
:for viewing.
:
:
:
:
:73's de Edd
:
:
:
:
:
::Hello Again,
:: I guess nobody knows then. Should I send a picture?
::
::Thanks,
::
::Dave
:::Hello All,
::: It turns out that the entire tuning mechanism slips when the set is tapped or subjected to vibration. How can it be tightened up so it cannot slip so much? What areas should be looked at? Could a spring be weak? It looks as if the radio was dropped at one time. There was a dent made by the tuning shaft in the nose piece. That was pretty much hammered out. There is a thin brass disc at the other end of the tuning shaft near where the shaft's geared end meshes with the tuning gear. It was bent too. I straightened it out. Something else is probably bent preventing something else from exerting pressure somewhere so that the tuning mechanism cannot slip. But I don't know where that is.
:::
:::Please help me find it.
:::
:::Thanks,
:::
:::Dave
:::
:::If the set is tuned to a station and not tapped and there is no vibration, the radio continues playing that station until it's shut off or tuned to another station.