Kd1mu Radio Store
kd1mu-radio.bsky.social
Kd1mu Radio Store
@kd1mu-radio.bsky.social
Quality products and US based support for Amateur Radio and GMRS operators.
These aren’t your low cost volume batteries. They are designed for ham radio and emergency comms. Only available on Kd1mu-radio.com and Amazon.com/shops/kd1mu-radio
April 21, 2025 at 8:20 PM
Happy Easter.
April 20, 2025 at 2:25 PM
Building an amp controller. Have all the measurement pieces in place. Main goal of the controller is to keep the radio from overdriving the amp and blowing the chip. The controller won’t allow the amp to engage if the power from the radio exceeds 5 watts. Ran a few tests and it seems to work.
April 8, 2025 at 8:12 PM
Designed for Amateur radio operators KD1MU products are low cost and high performing. Available on the kd1mu-radio.com website, Amazon, and AliExpress. Not all products in stock on all platforms.

kd1mu-radio.com
Amazon.com/shops/kd1mu-radio
www.aliexpress.com/store/1104554245
April 1, 2025 at 4:19 PM
An ad from raw story and why you probably shouldn’t post article from there
March 25, 2025 at 6:23 AM
Stepped into the world of hotspots today with a $35 pi zero based hotspot and MMDVM modem. Works nicely and only took me an hour to set up. Most of that was setting up and communicating with Brandmeister.

My goal is to provide support for customers using the KD1MU DM-4R with hotspots. Next up DMR+
February 26, 2025 at 9:58 PM
Running low on POTA and SOTA batteries. Turns out they were more popular than expected. Surprising uses are portable repeaters charged with solar panels. I decided to try it out and am running one on my roof. Using a chain link fence top rail as a 10’ mast for the antenna.

Kd1mu-radio.com
February 22, 2025 at 1:59 PM
I was at the dealership getting my yearly checkup and in the showroom was a Valentine’s Day present for someone.
February 15, 2025 at 2:03 AM
Finished the Drake PS-4 power supply rebuild. After some measurements that checked out, I am about to try the supply with my T4X-B. If it works, the idle current will go to .0707 amps. If it does, expect a lot of magic smoke. The plate voltage is 650.

Bias voltage reads -55 volts.
January 5, 2025 at 11:44 PM
This is one of my 20AH batteries designed for ham operators. Instead of using a 20 amp power plate, I am using a 40 amp plate. That means it is capable of more than 20 amps continuous. Look how easily it drives the 7300 to 100 watts CW.
January 4, 2025 at 4:22 PM
This is one of my current projects. I am rebuilding a 50 year old Drake PS-4 power supply for my T4X-B. The supply was working fine, but I did want a supply failure to ruin a great radio. So far I have removed the HV section and am rebuilding it with a Harbach kit.
January 4, 2025 at 4:11 PM