Topics

Bayou Jumper?


Retired Doc
 

Hi All,

I am finishing up the build and ready to test drive before buttoning it up.  I am not sure whether I should depress the wings on the sides of the molex pins (crystal socket) so that I can remove the cover (plastic bushings) if I need to and they will slide off.  I am  building (the latest version) rev A(c) (Green board)?  I wonder what others have done?  Thanks.

Kent KC9LIF


Bob Parr
 

I don't think the wings will prevent you from taking the plastic parts off. I am pretty sure I have already done it once.

Bob
KG5GTE

Hi All,

I am finishing up the build and ready to test drive before
buttoning it up. I am not sure whether I should depress the wings
on the sides of the molex pins (crystal socket) so that I can
remove the cover (plastic bushings) if I need to and they will
slide off. I am building (the latest version) rev A(c) (Green
board)? I wonder what others have done? Thanks.

Kent KC9LIF


Duane Brayton
 

Wings are not a factor. Molex female pins stay on bottom board when top board comes off.
Duane KE0IUV

Sent from TypeApp

On Apr 27, 2018, at 5:06 PM, Bob Parr <parr@...> wrote:
I don't think the wings will prevent you from taking the plastic parts off.  I am pretty sure I have already done it once.

Bob
KG5GTE

Hi All,

I am finishing up the build and ready to test drive before
buttoning it up. I am not sure whether I should depress the wings
on the sides of the molex pins (crystal socket) so that I can
remove the cover (plastic bushings) if I need to and they will
slide off. I am building (the latest version) rev A(c) (Green
board)? I wonder what others have done? Thanks.

Kent KC9LIF





Duane Brayton
 

Plastic sleeves  need to be removed first and reinstalled last when taking top board off.  I just slide the edge of my knife blade under the flange of the sleeve and rotate the blade to pull the sleeve up. 
Duane KE0IUV

Sent from TypeApp

On Apr 27, 2018, at 6:47 PM, Duane Brayton <dwbrayton@...> wrote:
Wings are not a factor. Molex female pins stay on bottom board when top board comes off.
Duane KE0IUV

Sent from TypeApp
On Apr 27, 2018, at 5:06 PM, Bob Parr < parr@...> wrote:
I don't think the wings will prevent you from taking the plastic parts off.  I am pretty sure I have already done it once.

Bob
KG5GTE

Hi All,

I am finishing up the build and ready to test drive before
buttoning it up. I am not sure whether I should depress the wings
on the sides of the molex pins (crystal socket) so that I can
remove the cover (plastic bushings) if I need to and they will
slide off. I am building (the latest version) rev A(c) (Green
board)? I wonder what others have done? Thanks.

Kent KC9LIF





Jess Gypin
 

You have to be able to take the plastic covers off or you won’t be able to remove the front panel.

Jess AE0CW

On Apr 27, 2018, at 4:06 PM, Bob Parr <parr@parrstreet.com> wrote:

I don't think the wings will prevent you from taking the plastic parts off. I am pretty sure I have already done it once.

Bob
KG5GTE

Hi All,

I am finishing up the build and ready to test drive before
buttoning it up. I am not sure whether I should depress the wings
on the sides of the molex pins (crystal socket) so that I can
remove the cover (plastic bushings) if I need to and they will
slide off. I am building (the latest version) rev A(c) (Green
board)? I wonder what others have done? Thanks.

Kent KC9LIF


Retired Doc
 

Thanks, Guys for the input.  I pushed the wings in a little so the contacts are centered in the bushing, but the bushing can slide of easily.

Kent KC9LIF


Bob Parr
 

I know there are some extra steps advised if you are going to connect a BJ to an external speaker or powered speakers. Does the Soup'r Up'r take care of that? Or would I still need to make a special connector cable with caps?

Bob
KG5GTE


Jeff Fein
 

If you are using a powered speaker you should be able to plug the pick up into the headphone jack, I would think!

Jeff
VK3GMO

-----Original Message-----
From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of Bob Parr
Sent: Monday, April 30, 2018 12:48 PM
To: main@4SQRP.groups.io
Subject: [4SQRP] Bayou Jumper?

I know there are some extra steps advised if you are going to connect a BJ to an external speaker or powered speakers. Does the Soup'r Up'r take care of that? Or would I still need to make a special connector cable with caps?

Bob
KG5GTE


Jim, N5IB
 

The Soup'er does NOT provide any DC isolation on the speaker lines.
So you still need to make sure that neither audio output lead has a DC path to ground, as you saw in the Appendix of the manual.

If you have one of the newest, rev A(c), circuit boards, there are some extra pads provided (JP2 and JP3) where the appropriate blocking capacitor(s) can be mounted. Then you cut the exposed trace(s) between the pad(s) on the bottom side of the board to put the cap(s) into the circuit.

A powered speaker with a self-contained battery supply can be used without needing a DC block. But if either of the external speaker connections has a DC path to the same ground as the BJ (like back through a wall wart power supply) it would short out and damage the audio chip.

N5IB


Bob Parr
 

You guys are so awesome. I love this kit more and more every day. Okay I have two caps that were leftover or found from another project. They are both tiny brown/tan caps. One says 719 then under that RMJ (may be AMJ) The other 10. Can either or both of these be used?

Bob
KG5GTE

The Soup'er does NOT provide any DC isolation on the speaker lines.
So you still need to make sure that neither audio output lead has a
DC path to ground, as you saw in the Appendix of the manual.

If you have one of the newest, rev A(c), circuit boards, there
are some extra pads provided (JP2 and JP3) where the appropriate
blocking capacitor(s) can be mounted. Then you cut the exposed
trace(s) between the pad(s) on the bottom side of the board to put
the cap(s) into the circuit.

A powered speaker with a self-contained battery supply can be used
without needing a DC block. But if either of the external speaker
connections has a DC path to the same ground as the BJ (like back
through a wall wart power supply) it would short out and damage
the audio chip.

N5IB


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Jim, N5IB
 

The cap marked "10" is most likely the 10 pF cap included in the Bayou Jumper kit in case you needed to use it at C20a to lower the receive tuning range.

There would have also been a 22 pF cap to be used if needed at C31.

The "719" doesn't seem like a standard capacitor marking. Anything on the other side of it?

N5IB


Bob Parr
 

Yes the back side was 220 A1K.

Can these be used for the DC blocking?

Bob
KG5GTE

The cap marked "10" is most likely the 10 pF cap included in the
Bayou Jumper kit in case you needed to use it at C20a to lower the
receive tuning range.

There would have also been a 22 pF cap to be used if needed at C31.

The "719" doesn't seem like a standard capacitor marking. Anything
on the other side of it?

N5IB


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Jim, N5IB
 

That'll be the 22 pF cap for use at C31 if needed.
The "220" means 22 x (10 to the power zero) = 22 x 1 = 22 pF

Much to small a capacitance to use for the DC block at the audio output. That will have to be a few micro farads, at least.

N5IB


Bob Parr
 

Where are JP 2 and 3? I only see JP1 on the manual. I know mine is a rev A but I am not sure if it is an A(c).

Bob

The Soup'er does NOT provide any DC isolation on the speaker lines.
So you still need to make sure that neither audio output lead has a
DC path to ground, as you saw in the Appendix of the manual.

If you have one of the newest, rev A(c), circuit boards, there
are some extra pads provided (JP2 and JP3) where the appropriate
blocking capacitor(s) can be mounted. Then you cut the exposed
trace(s) between the pad(s) on the bottom side of the board to put
the cap(s) into the circuit.

A powered speaker with a self-contained battery supply can be used
without needing a DC block. But if either of the external speaker
connections has a DC path to the same ground as the BJ (like back
through a wall wart power supply) it would short out and damage
the audio chip.

N5IB


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Jim, N5IB
 

JP2 and JP3 are only on the rev A(c) boards.
You can find that "revA(c)" designation on the silk screened legend just above the L5 and L6 on the top side of the main board.
The earlier green panel main boards are just "revA"

N5IB


Bob Parr
 

Darn. no 'c'. Well still like the way you guys think! The manual said at least 1 uf. would 10 be better? Also it says if using electrolytic with polarity, Positive side to the tip and or ring of the headphone jack. Assuming I put these caps in the board as opposed to making a cable, I would put the positive side to the board and negative to the tip and ring of the jack?

Bob
KG5GTE

JP2 and JP3 are only on the rev A(c) boards.
You can find that "revA(c)" designation on the silk screened
legend just above the L5 and L6 on the top side of the main board.
The earlier green panel main boards are just "revA"

N5IB


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Jim, N5IB
 

The two output pins of the NJM2113 audio amp chip (U1) are each biased at about 6 volts DC. That's why they can't be allowed to be grounded - it shorts out the bias voltage and zaps the output stage.

So you are correct - if you are using polarized capacitor(s) for DC blocking, the positive lead(s) should be connected towards the chip's pin(s)

You might get away with just one capacitor - in series with the ring terminal. That's the terminal that's likely to get grounded if using a powered speaker, or a speaker with a mono plug that has a ground path. But you have to be sure that the tip terminal of your external device doesn't have a DC path to ground somehow. Many powered speakers or audio filters already have a blocking capacitor in series with their input. Check their schematic or physically inspect the device if possible. If you're not sure, put caps in both leads.

Value depends on what is to be connected. Many powered speakers or audio filters have a fairly high input impedance, so a smaller capacitor is sufficient.
For example - suppose the input impedance is 100K. At 300 Hz, even as small as a 0.1 uF cap has a reactance of only about 5K. So it would not introduce very much voltage drop. But if the input impedance were like that of a normal speaker or headphone (a few tens of ohms), very little signal would get through.

This is why putting the capacitor in the external cable can be a convenience. You won't interfere with the normal use of your headphones, and only a smaller value capacitor(s) will probably be needed.

If the capacitor(s) get installed between the PC board and the headphone jack, and if you still intend to use headphones on occasion, the the capacitor(s) will need to be much larger - probably at least 10 uF, but need not be larger than 50 uF or so.

N5IB


Bob Parr
 

Okay, to be clear, if I really want to put the caps on the board, but want
to keep the most flexibility, 10 - 50 uf would be a decent compromise?

Bob
KG5GTE

The two output pins of the NJM2113 audio amp chip (U1) are each biased at
about 6 volts DC. That's why they can't be allowed to be grounded - it
shorts out the bias voltage and zaps the output stage.

So you are correct - if you are using polarized capacitor(s) for DC
blocking, the positive lead(s) should be connected towards the chip's
pin(s)

You might get away with just one capacitor - in series with the ring
terminal. That's the terminal that's likely to get grounded if using a
powered speaker, or a speaker with a mono plug that has a ground path.
But you have to be sure that the tip terminal of your external device
doesn't have a DC path to ground somehow. Many powered speakers or audio
filters already have a blocking capacitor in series with their input.
Check their schematic or physically inspect the device if possible. If
you're not sure, put caps in both leads.

Value depends on what is to be connected. Many powered speakers or audio
filters have a fairly high input impedance, so a smaller capacitor is
sufficient.
For example - suppose the input impedance is 100K. At 300 Hz, even as
small as a 0.1 uF cap has a reactance of only about 5K. So it would not
introduce very much voltage drop. But if the input impedance were like
that of a normal speaker or headphone (a few tens of ohms), very little
signal would get through.

This is why putting the capacitor in the external cable can be a
convenience. You won't interfere with the normal use of your headphones,
and only a smaller value capacitor(s) will probably be needed.

If the capacitor(s) get installed between the PC board and the headphone
jack, and if you still intend to use headphones on occasion, the the
capacitor(s) will need to be much larger - probably at least 10 uF, but
need not be larger than 50 uF or so.

N5IB





Jim, N5IB
 

10 to 25 uF would probably be fine if you just need one capacitor. But if you're using two, remember that they will be in series, and the equivalent capacitance will be half as great as the individual ones.

N5IB


Bob Parr
 

What happened here? This place used to be jumpin'. Now all I hear are crickets.

Bob
KG5GTE

Okay, to be clear, if I really want to put the caps on the board,
but want to keep the most flexibility, 10 - 50 uf would be a decent
compromise?

Bob
KG5GTE

The two output pins of the NJM2113 audio amp chip (U1) are each
biased at about 6 volts DC. That's why they can't be allowed to
be grounded - it shorts out the bias voltage and zaps the output
stage.

So you are correct - if you are using polarized capacitor(s) for
DC blocking, the positive lead(s) should be connected towards the
chip's pin(s)

You might get away with just one capacitor - in series with the
ring terminal. That's the terminal that's likely to get grounded
if using a powered speaker, or a speaker with a mono plug that
has a ground path. But you have to be sure that the tip terminal
of your external device doesn't have a DC path to ground somehow.
Many powered speakers or audio filters already have a blocking
capacitor in series with their input. Check their schematic or
physically inspect the device if possible. If you're not sure,
put caps in both leads.

Value depends on what is to be connected. Many powered speakers
or audio filters have a fairly high input impedance, so a smaller
capacitor is sufficient.
For example - suppose the input impedance is 100K. At 300 Hz,
even as small as a 0.1 uF cap has a reactance of only about 5K.
So it would not introduce very much voltage drop. But if the
input impedance were like that of a normal speaker or headphone
(a few tens of ohms), very little signal would get through.

This is why putting the capacitor in the external cable can be a
convenience. You won't interfere with the normal use of your
headphones, and only a smaller value capacitor(s) will probably
be needed.

If the capacitor(s) get installed between the PC board and the
headphone jack, and if you still intend to use headphones on
occasion, the the capacitor(s) will need to be much larger -
probably at least 10 uF, but need not be larger than 50 uF or so.

N5IB

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