TS-930 and TS-940 kits now available!

Both supply upgrades have been proven to work very well and are easy to install. Get yours on order today!

Kenwood Supply UPGRADE News

TS-930 Power Supply Upgrade

The TS-930 power supply upgrades are awesome and really easy to install! In most cases, you don't need a soldering iron. See us at SEA-PAC June 1-3 in Seaside, Oregon.

TS-930 Power supply removal video is online

We just posted the TS-930 power supply removal video - watch it and see how easy it is to remove the original supply from the TS-930!

Now shipping internationally

We are now shipping our products internationally. From the shopping cart, after you enter your address information all of the shipping options can be selected. Thanks for your patience with this!

We will be at RENO - July 20-21

We have a booth ordered for the SEAPAC convention which will be held from June 1 through June 3 in Seaside, Oregon. In addition to exhibiting, Jeff will be holding a demonstration on how to upgrade the power supply in a TS-940 and then after the seminar is over, we will be giving the radio away!

TS-930 Schematic diagrams now available

Last week we started wrapping up the design of some large schematics for the TS-930. In the original Service manual, there are a total of 4 fold out schematics that we are making available in large formats. There are 2 schematics for each of the serial number ranges.  One set covers  SN 208XXXX-309XXXX and the other available set covers  SN 310XXX and later. 

TS-940S Schematics now shipping

We are now shipping the TS-940S schematic diagrams, printed on high gloss photo paper. This is a single diagram containing all of the TS-940 modules along with the Main Schematic. 

What is this project all about?

Kenwood TS-940/TS-930 Supply Upgrade Project

After being a Ham for over 50 years, I have finally decided that one of the best transceivers ever made is the Kenwood TS-940. One of the biggest problems with the TS-940 has been the power supply. The supply on a working radio can tend to run at very high temperatures even in receive mode. 


Compudigital Industries has designed a full power supply upgrade that is  available now for purchase. We have finished the final testing on the TS-940 Supply upgrade and plan to release the TS-930 upgrade and make it available as well. The replacement of the supply allows the radio to run at room temperature instead of self destructing because the supply is so hot! 


To see videos regarding the upgrades, click on the Videos button at the top of the page.

Jeff - AK6OK

Big Schematics

Ham Radio schematics are really tough to follow, especially when our old eyes can't quite follow small lines on the page like we used to. If you are a Collins kind of guy, Compudigital has a full line of large schematics for most Collins models. You can check out our site at www.bigschematics.com to see what we have so far to offer! We will soon be producing large schematics for the entire Kenwood radio line as well. 


One of the unique additions we have made to the Collins schematics is color annotation. Our team has added different colors to the different signal paths allowing you to easily follow signals through the diagram. If the demand is 


If you would like to see a diagram that we do not offer, please contact me using the Send a Message link below.


West Coast Swap Service LIVE!

The West Coast Swap Service happens almost every weekend on 7.240Mhz covering Northern California at 12:30PM PST. You can listen to the swap live by clicking on the link above. soon, you will be able to email your listings into the swap administrator and your listing will be read live here on this site. The world of the West Coast Swap Service has just gotten a bit bigger!


The receiver for the Swap Net is in Auburn, California and the antenna is a 540 foot loop. The receiver is a TS-940S that has been modified with the new 20A switching power supply and interface kit  that is being sold on this site. 

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TS-940 Supply Upgrade - FAQ

NEW TS-940S Supply Upgrade Board

How much current does a TS-940 need?

In extensive testing using the TS0940 upgrade board, the radio requires 28V @ 14A, 21V @ 1.5A, 9V@ 250ma, and 5V at under 1A. The 28V supply is used exclusively for the final output stage. The switching power supply should be able to supply 28V @ about 15A peak. 

When is the upgrade for the TS-940 going to be ready?

The latest board is working perfectly and will be ready to ship by 2-1-2018. You can order the boards now. Use the Order Now link above to place your order.

Can I use an external power supply for the TS-940?

Yes! - Using just our supply upgrade board and a single buck converter for 21V, you can use your external 28V supply to run your TS-940. The board will be available as a kit and assembled so you can use your own 28V external power supply to run the radio.

Are we building a supply upgrade for the TS-930?

Yes! We are in development on the TS-930 supply upgrade board at this time and will be entering the testing stages in a few weeks. That process take about 30-45 days and then we should begin production. 

Why are these internal power supplies such a problem?

The original TS-940 uses a linear power supply that outputs 28V, 21V, 10V, and 5V. The power transformer and bridge output combination starts with almost 40 volts which feeds all of the other circuits to drop the various voltages accordingly. When you start with 40 volts and drop it to 28V at 14A, things are going to get hot. The TS-940 can easily run 150 degrees when in receive mode. And when you transmit, it will get hotter. These excessive temps cause component failures. A shorted power supply pass transistor can easily destroy all of the boards in the radio. This supply upgrade normally runs at room temperature and can prevent a future catastrophic failure.

What is the supply upgrade for the TS-940 going to cost?

The Quint 20A power supplies retail at over $400. We have made a special purchase of 250 supplies and will be offering a New Quint supply and upgrade board assembled and tested for around $300. If you wish to use your own external power supply, the Board alone with all components and cables assembled will be sold for about $165. The store is online now and we are accepting new orders.. 

What we have learned about the TS-940

The Kenwood TS-940 is the best HF radio ever made!

The receiver is amazing, and the transmitter puts out more power than your average transceiver these days. It our testing, we can hear signals as low as .05 microvolts! I have never seen a radio that can perform that well. The design is amazing based on the age of the radio. But new technologies allow us to replace the power supply with a much more efficient option. The new Quint Phoenix switching power supplies have very little noise and an expected life of 500,000 hours. There are other power supplies and other brands that will work just fine as well. But the Quint supply fits perfectly within the case and leaves plenty of room to install an interface board to wrap the project up easily. 

There are a few common issues with the TS-940

Common issues include:

1. A complete power supply failure which can damage the entire radio. 

2. A shorted output transistor in the original power supply puts up to 40V through the entire radio and can render it useless. 

3. Low output power is common and much of the time caused by an RF output driver transistor that is no longer available. 

4. A faulty attenuator resistor commonly shows up when the receiver hears better when the attenuation control is in the -10db or -20db range instead of the 0db selection. 

5. The display produces dots instead of the normal frequency displayed numbers.

6. When you turn on the radio, the only thing that happens is the LCD backlight comes on.

7. The radio is completely dead... We love this problem. Might just have a dead power supply!

8. There are some modifications that can be made to enhance the receiver

9. The soldering technology back then was pretty bad and many of the problems today can be associated with cold solder joints. 

Can these common problems be solved?

Most of these problems can be resolved by a technician with the proper tools,  test equipment, and of course the knowledge. There might be hams in your area that have the ability to make these repairs as well. As a part of the services we plan to provide, we will be posting not only these issues but also will be providing links to other sites that address these issues with some clarity.