For what is a crystal spotter used?


Jim, N5IB
 

A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter. If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was. His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending "callsign callsign de mycall mycall AR" is makes it much easier for that poor schmuck :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS.... -AK


Bob Parr
 

Thank you for such a through explanation!
 
Bob
KG5GTE

> A crystal spotter is just a simple oscillator which will emit a
> very low level signal when a crystal is attached. It's used to
> locate the crystal's operating frequency in a receiver, when the
> receiver is not slaved to the same oscillator as its companion
> transmitter.
>
> It's very useful with the Bayou Jumper, which has a wide pass band
> regenerative receiver, completely independent of the transmitter.
> If you're calling CQ with a Bayou Jumper you need to know where on
> the receiver dial to look for replies, since most operators using
> modern VFO controlled transceivers will zero beat your signal. It
> also helps to find out if there is other activity on your crystal
> frequency so you won't QRM them.
>
> The spotter does not have to be connected to the receiver, just
> placed nearby. Enough signal leaks out to be easily heard.
>
> BTW - whenever you are the "other op" trying to call and work a
> Bayou Jumper, remember that poor fellow has a regen. It's wide as a
> barn door, very sensitive, but he has to manually throw a switch
> and then perhaps tweak the tuning a bit to get back to where he
> was.  His or her tuning may be as much as a couple kHz or more from
> a dead-on zero beat. So the typical "drop your call once" won't cut
> it.
> Sending  "callsign  callsign   de   mycall  mycall   AR" is makes
> it much easier for that poor schmuck  :^))
> Back in the "spy days" the home station would call the outstation
> for several minutes to allow time for the hard pressed agent to get
> everything tweaked up.
>
> second BTW - because of all this, a Jumper-to-Jumper QSO is a real
> challenge and an accomplishment to be savored.
>
> Jim, N5IB
> 007
> Bayou Jumper almost WAS....   -AK
>
>
>


griffithsesq.robert
 

Thanks Jim. After reviewing the schematic diagram of your Crystal Spotter, I was trying to figure out how/where it was connected to the Bayou Jumper. A Bayou “Blue Tooth” connection. Neat! 73. Griff NE3I

Robert Alan Griffiths

On Jan 7, 2021, at 3:51 PM, Jim, N5IB <n5ib@juno.com> wrote:

A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter. If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was. His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending "callsign callsign de mycall mycall AR" is makes it much easier for that poor schmuck :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS.... -AK






wb6ogd
 

Hey guys,
I joined you group just to educate myself on another rig that's out there.
So, I don't really have a dog in this show but...

It seems to me that you could just make a simple mod to the Jumper, why do you need a whole
new gadget.
You just need to power the oscillator and cut power(or drive) to the final like all old novice type
transmitters did it.

If you take the crystal out of the FET Jumper oscillator and put it in an external bipoler oscillator,
are you sure its even going to be on the same frequency?  Ok, with a regen receiver a few KHz
isn't really going to matter.  Can't you just put a mark on the Rx dial where your crystal frequencies
are?  Even if its off a little, when you call CQ (the only practical way to get a contact I would think),
with the regen selectivity, you are going to hear them over the large passband, no?

As another little kit project, ok, I can see that it will be fun and a little educational, but...
Back to my hole,
73,
Gary
WB6OGD

On 1/7/2021 6:32 PM, griffithsesq.robert via groups.io wrote:
Thanks Jim. After reviewing the schematic diagram of your Crystal Spotter, I was trying to figure out how/where it was connected to the Bayou Jumper. A Bayou “Blue Tooth” connection. Neat! 73. Griff NE3I

Robert Alan Griffiths
On Jan 7, 2021, at 3:51 PM, Jim, N5IB <n5ib@juno.com> wrote:

A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter. If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was. His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending "callsign callsign de mycall mycall AR" is makes it much easier for that poor schmuck :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS.... -AK








John Parker
 

So, is the crystal spotter for the original bayou jumper or can it be used for both the older and the newest version that I just bought?

Mahalo,

John WH6DQU 


On Thu, Jan 7, 2021 at 10:51 AM Jim, N5IB <n5ib@...> wrote:
A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion  transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter.  If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was.  His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending  "callsign  callsign   de   mycall  mycall   AR" is makes it much easier for that poor schmuck  :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS....   -AK







Johnny AC0BQ
 

Gm John 
Any crystal.
The radio doesn’t matter, it’s stand alone.
Johnny ACØBQ 

On Thu, Jan 7, 2021 at 10:33 PM John Parker <parkjv1@...> wrote:
So, is the crystal spotter for the original bayou jumper or can it be used for both the older and the newest version that I just bought?

Mahalo,

John WH6DQU 


On Thu, Jan 7, 2021 at 10:51 AM Jim, N5IB <n5ib@...> wrote:
A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion  transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter.  If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was.  His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending  "callsign  callsign   de   mycall  mycall   AR" is makes it much easier for that poor schmuck  :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS....   -AK






--
Check out the 4SQRP website at 4sqrp.com


Mark Sharef
 

Why not a dummy load and an antenna switch.  Look at the qrpme super tuna 2 plus. 


On Fri, Jan 8, 2021 at 7:53 AM Johnny AC0BQ <jomatlock@...> wrote:
Gm John 
Any crystal.
The radio doesn’t matter, it’s stand alone.
Johnny ACØBQ 

On Thu, Jan 7, 2021 at 10:33 PM John Parker <parkjv1@...> wrote:
So, is the crystal spotter for the original bayou jumper or can it be used for both the older and the newest version that I just bought?

Mahalo,

John WH6DQU 


On Thu, Jan 7, 2021 at 10:51 AM Jim, N5IB <n5ib@...> wrote:
A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion  transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter.  If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was.  His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending  "callsign  callsign   de   mycall  mycall   AR" is makes it much easier for that poor schmuck  :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS....   -AK






--
Check out the 4SQRP website at 4sqrp.com


Johnny AC0BQ
 

gm Mark 
See the previous postings! 
72 
Johnny 

On Fri, Jan 8, 2021 at 10:07 AM Mark Sharef <hamradio.wq8s@...> wrote:
Why not a dummy load and an antenna switch.  Look at the qrpme super tuna 2 plus. 

On Fri, Jan 8, 2021 at 7:53 AM Johnny AC0BQ <jomatlock@...> wrote:
Gm John 
Any crystal.
The radio doesn’t matter, it’s stand alone.
Johnny ACØBQ 

On Thu, Jan 7, 2021 at 10:33 PM John Parker <parkjv1@...> wrote:
So, is the crystal spotter for the original bayou jumper or can it be used for both the older and the newest version that I just bought?

Mahalo,

John WH6DQU 


On Thu, Jan 7, 2021 at 10:51 AM Jim, N5IB <n5ib@...> wrote:
A crystal spotter is just a simple oscillator which will emit a very low level signal when a crystal is attached. It's used to locate the crystal's operating frequency in a receiver, when the receiver is not slaved to the same oscillator as its companion  transmitter.

It's very useful with the Bayou Jumper, which has a wide pass band regenerative receiver, completely independent of the transmitter.  If you're calling CQ with a Bayou Jumper you need to know where on the receiver dial to look for replies, since most operators using modern VFO controlled transceivers will zero beat your signal. It also helps to find out if there is other activity on your crystal frequency so you won't QRM them.

The spotter does not have to be connected to the receiver, just placed nearby. Enough signal leaks out to be easily heard.

BTW - whenever you are the "other op" trying to call and work a Bayou Jumper, remember that poor fellow has a regen. It's wide as a barn door, very sensitive, but he has to manually throw a switch and then perhaps tweak the tuning a bit to get back to where he was.  His or her tuning may be as much as a couple kHz or more from a dead-on zero beat. So the typical "drop your call once" won't cut it.
Sending  "callsign  callsign   de   mycall  mycall   AR" is makes it much easier for that poor schmuck  :^))
Back in the "spy days" the home station would call the outstation for several minutes to allow time for the hard pressed agent to get everything tweaked up.

second BTW - because of all this, a Jumper-to-Jumper QSO is a real challenge and an accomplishment to be savored.

Jim, N5IB
007
Bayou Jumper almost WAS....   -AK






--
Check out the 4SQRP website at 4sqrp.com


Jim, N5IB
 

The question asked was, "why not just power the Bayou Jumper's oscillator, but not the PA, and just listen for the signal in the receiver?"

The answer is - The Bayou Jumper does in fact work exactly that way. When you press the key while in the receive mode, the oscillator is activated, but not the PA. It was designed to do that. The signal can be heard in the receiver. Great, just what's needed, right ?!

Well, not so much....

Remember, the receiver is a regen. That means that any strong signal will pull the receiver onto the signal frequency. And remember that the source of that signal (many many millivolts) is right on the same PC board, just a few cm away from the detector. The zero beat "point" on the dial ends up being a broad region, with no some strong over a fair amount of dial in the middle and squeals on either side.

Now, if you run the regeneration control all the way to max, run the attenuation all the way to max attenuation, and turn the AF gain way down, you can sometimes just about get away with it. But then you have to reset everything back to normal receiving. Much simpler to have a little oscillator sitting next to the rig. Touch the crystal to it, and a clearly discernible, but not overly strong, signal can be heard. Tune to zero beat, pop the crystal back in the rig (maybe mark the dial) and you're ready to roll. You'll hear everything with three of four kHz of the zero beat point.

Bottom line, there's just not an easy way to knock down the signal strength of the internal oscillator to the point where it will play nice with a regen detector. BTW - the original Paraset couldn't spot it's own signal either. The B+ was switched off the receiver during transmit. But, they didn't have to. They knew where to listen for London (definitely QRO!) , and London knew what crystals they had.

BTW - When David designed the Soup'er Up'er he had to fight that problem to get a working sidetone. The audio amp had to still be powered during Tx, but he had to knock down the Rx output with a MOSFET switch.

Jim, N5IB


 

Jim

With regards to spotting I also was never able to use the key down in RX to spot my frequency. As you mention the heterodyne is widely spaced and not very loud. By accident one day I tried using my Whiterook mini keyer (Tick-2 ) in the straight key mode. Without touching my regen or atten I now get a loud heterodyne with a small dead spot. I have no problem spotting almost exactly on 700 Hz.
It works great but I don’t know why. I’d be happy to take some measurements if anyone is interested. The only mod I have is the TIP42g transistor for the external keyer.

72
Peter
AA2VG

On Jan 8, 2021, at 7:53 PM, Jim, N5IB <n5ib@juno.com> wrote:

The question asked was, "why not just power the Bayou Jumper's oscillator, but not the PA, and just listen for the signal in the receiver?"

The answer is - The Bayou Jumper does in fact work exactly that way. When you press the key while in the receive mode, the oscillator is activated, but not the PA. It was designed to do that. The signal can be heard in the receiver. Great, just what's needed, right ?!

Well, not so much....

Remember, the receiver is a regen. That means that any strong signal will pull the receiver onto the signal frequency. And remember that the source of that signal (many many millivolts) is right on the same PC board, just a few cm away from the detector. The zero beat "point" on the dial ends up being a broad region, with no some strong over a fair amount of dial in the middle and squeals on either side.

Now, if you run the regeneration control all the way to max, run the attenuation all the way to max attenuation, and turn the AF gain way down, you can sometimes just about get away with it. But then you have to reset everything back to normal receiving. Much simpler to have a little oscillator sitting next to the rig. Touch the crystal to it, and a clearly discernible, but not overly strong, signal can be heard. Tune to zero beat, pop the crystal back in the rig (maybe mark the dial) and you're ready to roll. You'll hear everything with three of four kHz of the zero beat point.

Bottom line, there's just not an easy way to knock down the signal strength of the internal oscillator to the point where it will play nice with a regen detector. BTW - the original Paraset couldn't spot it's own signal either. The B+ was switched off the receiver during transmit. But, they didn't have to. They knew where to listen for London (definitely QRO!) , and London knew what crystals they had.

BTW - When David designed the Soup'er Up'er he had to fight that problem to get a working sidetone. The audio amp had to still be powered during Tx, but he had to knock down the Rx output with a MOSFET switch.

Jim, N5IB






--
Peter S. DeLuca
AA2VG


griffithsesq.robert
 

Jim. Thank you for this explanation and all of the time you give helping us with various issues that sometimes come up.73. Griff NE3I

Robert Alan Griffiths

On Jan 8, 2021, at 7:53 PM, Jim, N5IB <n5ib@juno.com> wrote:

The question asked was, "why not just power the Bayou Jumper's oscillator, but not the PA, and just listen for the signal in the receiver?"

The answer is - The Bayou Jumper does in fact work exactly that way. When you press the key while in the receive mode, the oscillator is activated, but not the PA. It was designed to do that. The signal can be heard in the receiver. Great, just what's needed, right ?!

Well, not so much....

Remember, the receiver is a regen. That means that any strong signal will pull the receiver onto the signal frequency. And remember that the source of that signal (many many millivolts) is right on the same PC board, just a few cm away from the detector. The zero beat "point" on the dial ends up being a broad region, with no some strong over a fair amount of dial in the middle and squeals on either side.

Now, if you run the regeneration control all the way to max, run the attenuation all the way to max attenuation, and turn the AF gain way down, you can sometimes just about get away with it. But then you have to reset everything back to normal receiving. Much simpler to have a little oscillator sitting next to the rig. Touch the crystal to it, and a clearly discernible, but not overly strong, signal can be heard. Tune to zero beat, pop the crystal back in the rig (maybe mark the dial) and you're ready to roll. You'll hear everything with three of four kHz of the zero beat point.

Bottom line, there's just not an easy way to knock down the signal strength of the internal oscillator to the point where it will play nice with a regen detector. BTW - the original Paraset couldn't spot it's own signal either. The B+ was switched off the receiver during transmit. But, they didn't have to. They knew where to listen for London (definitely QRO!) , and London knew what crystals they had.

BTW - When David designed the Soup'er Up'er he had to fight that problem to get a working sidetone. The audio amp had to still be powered during Tx, but he had to knock down the Rx output with a MOSFET switch.

Jim, N5IB