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Cricket 40 Mod


Daniel Walter
 
Edited

 Just finished my Cricket 40. Neat kit, thanks for the design. I made a modification that 4SQRP may be interested in. 
 
 You have the option of an integral straight key or an external key jack. I wanted both available at anytime. So I used the external key jack adapter and mounted it beside the straight key. I isolated a small pad from the ground plane and soldered a heavy wire over this pad to support the adapter strip and connect to the key pad. 
 
 I drilled holes through the ground plane to connect the other end of the adapter. I used washers to elevate the strip and keep the jack pins from shorting to ground. As this jack does not short when empty, this allows me to use the straight key (which I generally will do) and add an external keyer when I want. I used the space between to store my crystals. 
 
 You could modify the PCB to integrate the external key jack onto the board in a similar position to where I mounted mine. This would also eliminate need for the extra PCB strip. 
 
 I have attached photos showing my work. 
 
 72,73, Dan
 
 Sent from ARS: NM3A


Tom Sevart
 

Looks good. I personally installed an external key jack next to the on-board straight key by drilling a hole and putting in a 3.5mm mono jack. I connected that to a PNP transistor so I can use a keyer with the Cricket. That works better than trying to key the full 9V through the keyer. I also installed a yellow power LED and red TX LED in the board. The power LED is connected directly to power through a resistor, and the TX LED is connected to the PNP transistor so that it lights up when the rig is keyed.

--
Tom Sevart N2UHC
St. Paul, KS


Wayne Steury
 

I modified my 80 meter cricket. Great idea.



Wayne Steury N9EGT

On Jan 28, 2020, at 7:47 PM, Tom Sevart <tmsevart@...> wrote:

Looks good. I personally installed an external key jack next to the on-board straight key by drilling a hole and putting in a 3.5mm mono jack. I connected that to a PNP transistor so I can use a keyer with the Cricket. That works better than trying to key the full 9V through the keyer. I also installed a yellow power LED and red TX LED in the board. The power LED is connected directly to power through a resistor, and the TX LED is connected to the PNP transistor so that it lights up when the rig is keyed.

--
Tom Sevart N2UHC
St. Paul, KS



Karl Schwab
 


There is a easier way to modify the Cricket for a external key, and this was presented here some time ago.  The key knob was added to external key strip by cutting a trace, and adding a single wire.  This is the only strip now on the PCB and works perfectly in both modes on my Cricket 80a.  I don't have that mod info in front of me, but it should be able to be found with some research.  73, Karl, KO8S

On Tuesday, January 28, 2020, 12:31:42 PM EST, Daniel Walter via Groups.Io <nm3a@...> wrote:


[Edited Message Follows]

 Just finished my Cricket 40. Neat kit, thanks for the design. I made a modification that 4SQRP may be interested in. 
 
 You have the option of an integral straight key or an external key jack. I wanted both available at anytime. So I used the external key jack adapter and mounted it beside the straight key. I isolated a small pad from the ground plane and soldered a heavy wire over this pad to support the adapter strip and connect to the key pad. 
 
 I drilled holes through the ground plane to connect the other end of the adapter. I used washers to elevate the strip and keep the jack pins from shorting to ground. As this jack does not short when empty, this allows me to use the straight key (which I generally will do) and add an external keyer when I want. I used the space between to store my crystals. 
 
 You could modify the PCB to integrate the external key jack onto the board in a similar position to where I mounted mine. This would also eliminate need for the extra PCB strip. 
 
 I have attached photos showing my work. 
 
 72,73, Dan
 
 Sent from ARS: NM3A


Daniel Walter
 

There were 2 previous mods. The one used a transistor to lower the keying current. It seemed slightly more complicated but apparently allowed for simultaneous use of an external keyer and the straight key. The other mod I had thought of but discarded as it requires a shorting plug, which is another thing to get lost, and a way to hold the key down when the external keyer is used. The extra strip was already there and it requires only a wire and two extra nuts and bolts. And, most importantly to me, both the external keyer and the straight key can be used at the same time with no other items.


Best would be having the jack right on the PCB and no extra strip. Easy to incorporate into a new PCB design, but a little harder to mod the existing one. 
--
72/73, Dan
NM3A


Karl Schwab
 


The attached photo is of my Cricket 80a that was modified per a post here from a year or so ago, allowing for the use of the straight key or keyer input.  It was a simple mod of cutting a PCB trace and adding a single length of wire.  Neither of which can be seen in this photo.  The short length of wire is directly under the straight key strip.  The mod was nice and clean and works perfectly and should be done on all Cricket builds, in my opinion.  73, de Karl, KO8S

On Friday, February 7, 2020, 10:53:24 AM EST, Daniel Walter via Groups.Io <nm3a@...> wrote:


There were 2 previous mods. The one used a transistor to lower the keying current. It seemed slightly more complicated but apparently allowed for simultaneous use of an external keyer and the straight key. The other mod I had thought of but discarded as it requires a shorting plug, which is another thing to get lost, and a way to hold the key down when the external keyer is used. The extra strip was already there and it requires only a wire and two extra nuts and bolts. And, most importantly to me, both the external keyer and the straight key can be used at the same time with no other items.


Best would be having the jack right on the PCB and no extra strip. Easy to incorporate into a new PCB design, but a little harder to mod the existing one. 
--
72/73, Dan
NM3A


Daniel Walter
 

Karl,
Do you have the schematic for your mod?  Do you need a shorting jack?
Dan
--
72/73, Dan
NM3A


Karl Schwab
 

Dan, I do not have, or there never was, a schematic for this mod, i.e., "adding keyer jack to straight key strip" (or some such words).  I took my Cricket 80a apart (see attached photo) so you can see how simple this was to do.  Again, this was not my idea, but a post to the 4sqrp groups here a year or more ago.  Looks like one pin of the jack was removed, then soldered to the board, two pins jumped, and a short length of wire added from one pin and soldered to pad on PCB.  The photo shows this.  Sorry, that is all that I have, but I have to say, it works like a charm buy using either the original straight key or attaching a keyer.  No shorting plug or anything else needs to be used.  I would like to see someone, research this mod and re-post it here.  I think I will order a Cricket 40 and build it using what I have done here. 73, Karl, KO8S

On Sat, Feb 8, 2020 at 11:14 AM Daniel Walter via Groups.Io <nm3a=yahoo.com@groups.io> wrote:
Karl,
Do you have the schematic for your mod?  Do you need a shorting jack?
Dan
--
72/73, Dan
NM3A


Daniel Walter
 

Thanks for the picture, Karl. I figured out the mods. Just as simple as my mod! But I didn't think of that.
--
72/73, Dan
NM3A


Karl Schwab
 

Good deal Dan; I just tried the Cricket 80a today, both straight key and keyer jack work perfectly!  I think this mod needs to be included in the kits, i.e., trace(s) added/removed from key PCB, whatever it takes.  Owners will want the keyer option at some point.  73, Karl, KO8S

On Sat, Feb 8, 2020 at 1:09 PM Daniel Walter via Groups.Io <nm3a=yahoo.com@groups.io> wrote:
Thanks for the picture, Karl. I figured out the mods. Just as simple as my mod! But I didn't think of that.
--
72/73, Dan
NM3A