FX Radar Hack

I shared this on Instagram the other day and thought some of you here might like it too.

I swapped out the AAA batteries in my FX radar for the Curt S Adler AAA to USB converter that I bought on Amazon for like $12. By doing so, I never have to change batteries again…Instead, I just use any of the many USB chargers or larger capacity batteries we have laying around. It works great, costs only $12 and the batteries I have been using last all day. It’s cheap and makes the FX Radar even more convenient. 

Have a great weekend!

Stoti

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I am thinking along the same lines, also now that i have moved away from bipod to a caldwell rest, i want to mount the FX chrono off that rest instead of the gun barrel, or a unsightly #2 carbon fiber rod fixed to the gun.

The inline chrono i was panting for, aside for it not selling yet, then the interest in that have faded too, but i am still liking the LCD much better than using the phone,,,,, a device i hate vigorously



Do that thing feed the 5V from USB or is there a step down "thingy" involved.
 
Thanks for the heads up. I had modified mine a while back by adding a DC socket for a USB power bank and that made the chronograph imminently more usable, but knowing this type of product is out there may be useful on a future project.

In case it saves others from searching, this appears to be the adapter:
https://www.amazon.com/Kurt-S-Adler-Converter-Connect/dp/B084SFKR7D


 
Do that thing feed the 5V from USB or is there a step down "thingy" involved.

I read over the product description and reviews and could find no evidence that it steps down USB’s 5V to 4.5V but I doubt it does. The vast majority of 3-cell devices are perfectly content with 5V.

I looked at the behavior of the regulators in the FX chrono before I applied 5V and it is fine with it too. So either way, the adapter would work with it.
 
nervoustrig

Read the reviews on Amazon yikes keep a fire extinguisher close by just incase.

Might want to keep it separate far away from the gun just incase.

Always good to know of any potential risks before buying any thing.

Rechargeable batteries preferably with high mAh could also be a safer option. Some rechargeable batteries are still made in Japan believe it or not. Research or if buying local flip the packages over to see where they are manufactured before buying if country of origin matters to you when paying similar prices.
 
nervoustrig

Read the reviews on Amazon yikes keep a fire extinguisher close by just incase.

Might want to keep it separate far away from the gun just incase.

Always good to know of any potential risks before buying any thing.

Rechargeable batteries preferably with high mAh could also be a safer option. Some rechargeable batteries are still made in Japan believe it or not. Research or if buying local flip the packages over to see where they are manufactured before buying if country of origin matters to you when paying similar prices.






Saw that too but there doesn’t look like any other alternatives on amazon or eBay or any other review stating a faulty unit.


BUT no issues at all for me so probably that was a faulty one that shorted, pretty easy to prevent fire by just unplug from the battery pack after finishing using it. It’s a common good practice to unplug when done so still well worth it IMHO. I had a hot string of over 400 shots from my range day with my impact! Woot!!! 
 
qball

Just guessing the thin wires connecting all 3 batteries together could have over heated or shorted.

Second negative review on Amazon stated the wires broke on one of his.

Here are othes found on line but don't know their safety or reliability either.

At least they don't have the thin wires connecting to each other.

Just replying to other alternatives and do not know how reliable they are.

There are many on eBay but looks like they are shipped from China any ways.

https://www.wish.com/product/5e6c90c57d4c2f3d9d6590c6?

Here is another.

https://m.aliexpress.com/item/4000801016028.html?
 
You know, Christian asked me about the voltage yesterday and I may have responded too quickly. The USB batteries I’ve been using are all 5v and work fine. I’ve got probably 16 hours of use so far without a problem. As far as stepping down to 4.5v, I don’t think so.


Really all this adapter is made of is three battery looking pieces that are the size of three AAA batteries, the three wires and the usb cord. It’s just a connection, very simple. It does work great though, especially for $12.


As Fx as overheating or whatever, I didn’t read the review but would assume it’s either a short or the battery. I taped the wires to make them more durable and don’t have a battery attached if I’m not using it. I unplug the battery, it’s too heavy to leave hanging from the wires hen I transport it. The other option would of course be standard rechargeable batteries but I don’t want to take the rear cover on and off every day.

As far as mounting it to my tripod, mine is threaded, so I just screws it on. 

Thanks for adding the link Trig!

Oh, I forgot… I taped the wires to the leg of my little tripod so I don’t accidentally pull them out. Probably a good thing to do if you buy one.

Everyone have a great weekend!

Stoti






 
For anyone interested in voltages and currents, here's what I recorded from mine.



FX pocket chronograph (PCB marked v2.4)
---------------------------------------
Low battery indicator triggers when Vbat < 3.80V
3.3V regulator is a linear LDO with ~100mV dropout
5.0V regulator is a buck/boost
current draw: 81mA @ 5.0V
89mA @ 4.0V
99mA @ 3.5V
114mA @ 3.1V
Most of the current draw is from the Bluetooth connection. With no connection to a smartphone, the current draw is <20mA.




Which reminds me, many of the USB power banks have an automatic cutoff when the current draw falls below a certain threshold. On the one I'm using, it's at 100mA. The chronograph pulls a bit less than that (80mA @ 5.0V) so I soldered a small resistor across the leads to draw about 25mA to kick it over the threshold so the power bank will stay on.
 
qball

Just guessing the thin wires connecting all 3 batteries together could have over heated or shorted.

Second negative review on Amazon stated the wires broke on one of his.

Here are othes found on line but don't know their safety or reliability either.

At least they don't have the thin wires connecting to each other.

Just replying to other alternatives and do not know how reliable they are.

There are many on eBay but looks like they are shipped from China any ways.

https://www.wish.com/product/5e6c90c57d4c2f3d9d6590c6?

Here is another.

https://m.aliexpress.com/item/4000801016028.html?




I definitely get what you are saying, the ribbon wire is very thin but it fits under the cover very nicely with zero pinch. To protect the thin wire I use masking tape to tape a loop of wire on the back of the chrono so there wont be any stress on the thin wire section from the wire/battery movements.