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Icom IC-705 USB-C/SEND Control Board Upgrade

Icom IC-705 USB-C/SEND Control Board Upgrade

Regular price $84.00 USD
Regular price Sale price $84.00 USD
Sale Sold out


Items now in stock 😎

We now have units ready to ship. Orders will be shipped within two business days after being placed.

Get 25% off on USB-C Cables with the purchase of an upgrade board!


This is a drop-in replacement control board (Connect Unit B-9128B) for the Icom IC-705 radio. Designed by Ben (KD9LJF), it is an easy upgrade for any IC-705 radio.

Installation Guide

We have a step-by-step picture installation guide on our website:

You can also find a video explanation and overview here:


The upgraded control board has a USB-C port that retains all of the original port's functionality (including computer data). This port is just a connector swap and works identically to the original board. This means that it does not add any USB-C Power Delivery (PD) features. You can still charge the radio through the USB connector with any USB-C charger, but it will still only charge at 5V and around 7.5W from the charger with the radio turned off.

SEND line

The SEND/ALC circuit has also been upgraded for additional protection for connecting external amplifiers. The original board from Icom was only capable of switching less than 30mA of current on the SEND line. Connecting an amplifier that operates by switching 12V to ground would likely fry your original board as it did for mine. Our new control board has upgraded MOSFETs for the SEND line that can switch up to 1.0 amp of current. We also added a Zener diode to protect against voltage spikes above 16V. Our upgrade to this circuit makes your 705 compatible with most 12V amplifiers without additional adapters other than the TRS 3.5mm cable.

Known Amp Compatibility List

Help us build an amplifier compatibility list! Message us with the amp model you've tested with the upgraded board.

So far, we have tested the following amps:

  • Homebrew 12V amp
  • TenTec Titan Amp (Vacuum Relay)
  • Xiegu XPA125B
  • Elecraft KXPA100
  • RM Italy HLA305 & MLA100

Please keep in mind that most amplifiers will work even if they are not directly listed on the compatibility list.

Warning against powered buffers

Powered buffers for the SEND line, such as the Ameritron ARB-702i, are known to damage both the stock control board and this replacement upgrade board. I advise against using them with this upgrade board and recommend connecting the amplifier directly to the control board.


The USB-C Control Board has a one-year warranty. (Warranty does not cover any damages to the radio.)

Installation Services

We offer installation services through our experienced technicians at iHelpU.Tech in Illinois if you do not want to install the upgrade yourself. Please message us for details.

International Sales

We are offering sales to most international markets. Shipping will be Through UPS, USPS, or DHL. Please message us if your market needs to be listed at checkout, and we will determine if we can add it. Some restrictions apply.


Update 03/19/24

We got more units in stock! We are working on getting all existing orders shipped out while fulfilling new orders. Expect to receive tracking info soon!

Update 03/07/24

Our next batch is almost done in the manufacturing stage. We expect them to arrive within a couple of weeks. Looking at our projections, we should have plenty left over after this order arrives to fill existing orders and have stock on hand. This will mean faster ship times from orders moving forward.

Update 01/22/24

Next batch of boards is sold out! We are taking orders now for a future run that we expect to ship out towards the beginning of March.

Update 01/11/24

The next run of boards is in production. We expect to receive them towards the end of this month or early next month. Testing of the units will begin after we receive them, and we will be shipping more units by mid-February.

Update 12/25/23

Merry Christmas, everyone! Special shoutout to my crew, Elizabeth, Frank, and Adrian, who all pitched in to complete quality control and packaging of the next batch of control boards. We were able to get the next 300 units tested and packaged last Thursday evening, and they shipped out on Friday, the 22nd. Please check your tracking numbers again for updates from the carrier.

We are still accepting pre-orders for our next manufacturing run. We are working with our manufacturing partner to fill all existing pre-orders and hopefully build some stock with anticipation of additional pre-orders. We expect to receive more units by late January.

I also created a new installation guide available here: This new guide is more detailed about the connector on the upgrade board since the video doesn't explain it in much detail. As always, please message us if you have any questions.

Update 12/9/23

Huge thanks to Josh at Ham Radio Crash Course for showcasing this upgrade board on his channel! You can watch his video here:

Thanks to his video and your support, all of the boards on the run of 300 have been spoken for! We expect to receive this order by the end of next week, and we will begin testing each one and getting them shipped out. We are working with our manufacturing partner to get another run going. We will do another run of 500 or 1000 boards, depending on time and cost. Order numbers #1304 and higher will be on this next run and can expect to receive your order in mid-late January.

Update 11/25/23

We received the next 100 boards! Our team has begun quality control and will ship out units next week. The remainder of our eBay orders have been fulfilled so orders from our online store will start shipping out. Keep an eye on your email for tracking numbers.

Update 11/14/23

The manufacturer finished our order of 100 boards! We should receive them by next week to start quality control testing. Once QC is complete, we will ship them out. The remaining orders will be filled on our order of 300 boards. They have finished making the PCB and are waiting for all the components to arrive.

Update 11/8/23

The first 20 units that were sold on eBay have been shipped out! If you placed your order on our eBay store in early-mid October, check your eBay account for a tracking number. If you see one, your order has been fulfilled and is on its way! If you don't have a tracking number, your order will be filled when the subsequent 100 units are ready. They are halfway through final assembly and will ship to us for QC soon.

Another 300 units have been ordered to meet demand and get some stock on hand built up. They will be here by mid-late December. Thanks for all of the support!

Update 11/6/23

The next 100 units are sold out! We are now accepting pre-orders for our next batch, which will arrive by mid-late December. Orders will be fulfilled by which they are received.

The batch of 100 has started component assembly. This process takes about a week, so we expect to receive them with shipping times in 2-3 weeks. We will perform QA and then ship them out to everyone. This is on target with our late November to early December ETA.

Update 11/1/23

The first 20 units we sold on our eBay list are sold out! They have shipped from our manufacturer, and we should receive them by the end of next week. The next 100 units can be pre-ordered here and will ship by mid-December.

Update 10/24/23

Thanks for all of the support! The first 20 units are almost sold out. The manufacturer has finished manufacturing the PCB and is waiting for all of the components to arrive so they can start assembly. They are on track so far, and we should be receiving them by the middle of November. We will ship them out as soon as we get them.
We confirmed another batch of 100 units that will be ready by late November or early December. We will be taking pre-orders for those units. They should be able to ship by Christmas if you order now. We will continue offering a 20% discount for pre-orders.

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Customer Reviews

Based on 39 reviews
Stefan Becker
Perfectly fine

Fast delivery to Germany -- everything's perfectly fine!

Andras Rakicsany
Amazing customer support, and product!

I installed the board in my ICOM radio for the USB-C and to use it with my Xiegu 125b amp. Under normal circumstances, this combination works great. It turns out my amp had a problem and fried the board. IHelpU replaced it without a hassle and shipped a new board to me! I'm impressed. Not many companies would have done this! Five stars!

Wim van der Zwan
Excellent mod for ic-705

Very fast delivery. Very good quality

jon hult
705 USBc

Fit perfect, worked out of the box, and keys the Micro PA50 amp perfectly. Good product!

Craig McVeay
Great piece, easy install

The board is well made and quite easy to install.