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Radioddity PAX100 RF Power Amplifier | 100W | Portable | Plug and Play | for Xiegu G90 X5105 [DISCONTINUED]

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SKU: 28-715-PAX100*SEC
  • Normaler Preis €186,06
  • Normaler Preis SAVE €-186,06

Only -1 left in stock

Limited Quantity

Radioddity PAX100 is a mini RF power amplifier DIY kit using MOSFETS and is specially designed for Xiegu G90 and X5105 radios. It can achieve 100W power output with an input power under 10W. The design is extremely compact and light-weight. Nothing like it is available in its power vs. size rating.

Must Know

1. A power supply capable of delivering 20 Amps current at 13.8 Volts is required.

2. When using PAX100, please turn off the built-in antenna tuner of G90, otherwise PAX100 will be damaged. (External tuner is allowed to use.)

3. The PAX100 requires a resonant antenna on every frequency it can operate on. If the antenna is not resonant, you will need an external Antenna Tuner. The tuner must be able to present an SWR to the output of the amplifier of less than 2.0:1. The lower the SWR is, the less chance of damage to the amplifier. Anything above 1.5: should be used with caution. The final transistors specifications recommend not exceeding 2.0:1. The internal tuner of the radio will not be useful then the amplifier is in use. If the SWR of the antenna in use is much higher than 1.5:1, after sustained operation, the amplifier may be damaged. At 2.5:1 or higher, the amplifier will be damaged and unusable until repaired.
If needed, the final transistors are available from general parts suppliers and are low-cost.

4. The input power (from the G90) to the amplifier should never exceed 10 Watts; even on SSB peaks. Driving the amplifier with an output from the G90 higher 10 watts will result in damage to the amplifier.

5. Amplifier’s gain is large on 160 meters. Please reduce drive to 5 watts on 160 meters.

6. Output with an open circuit or short circuit is prohibited.


What's New?

• Upgraded red PCB board & protective case

• Upgraded fuse box for the power cord

• Better soldering design


Up to 100W Power Output pecially Built for Xiegu G90 & X5105 Solid Material & Accessories

Up to 100W Power Output

This amp is capable of up to 100W output on 20 meters and below. 70 watts is typical in the higher bands. The amplifier connects to the G90 or X5105 to perform RX/TX switching. It uses two inexpensive 55-watt IRF 350’s as the final amplifier devices.

Specially Built for Xiegu G90 & X5105
Radioddity PAX100 is specially designed for Xiegu G90 & Xiegu X5105. It covers the 3 MHz~30MHz frequency range and modes including A1A (CW), J3E (SSB), A3E (AM), F3E (FM), F7M (C4FM), F1B (FSK).


Solid Material & Accessories
The PCB uses a double-layer immersion gold finish providing long and stable operational life.  It comes with an XT60 power supply connector which can easily handle its max current draw. Any type of power connector can be mated to it. Since it uses gold-plated SMA connectors, it comes with input and output adapter cables to male and female PL-259/PL-239 connectors. We also provide the PTT trigger cable. It can be used with ours and many other QRP radios.


Heat Dissipation Details Plug and Play Portable & Non-slip Design

Heat Dissipation Details

The amp uses a large aluminum heat sink. The whole PCB secures directly to this heat sink. High-conductivity interface materials are used to dissipate maximum heat and provide stable operation. A cooling fan is installed on one side of the heat-sink with 2 cooling modes. It is a low-noise model that provides excellent CFM.

Plug and Play

Different from other amplifier kits, Radioddity PAX100 comes with a PTT Trigger Cable connecting to the G90/X5105. Simply press the PTT key of G90/x5105 to transmit and PAX100 will automatically amplify the output power to 80-100W without any other operation.


Portable & Non-slip Design

It’s dimensions are (4.33 x 1.97 x 1.57 in). This DYI power amplifier kit only weighs 0.5lb. It is surprisingly small and has 4 non-skid pads on the bottom of the heat-sink. A beautiful clear poly-carbonate top mounts above the circuit board to protect it.



Frequency Range: 3 MHz~30MHz
Supported Modes: A1A (CW), J3E (SSB), A3E (AM), F3E (FM), F7M (C4FM), F1B (FSK)
Power Supply Voltage: DC 12V ~ 18V
Power Supply Current: Standby 0.2A | Transmit 12A maximum
Input SWR: <2.0: 1
Input / Output Impedance: 50 ohms (± 10%)
Through Loss: less than 0.5dB
Power Gain: greater than 15dB (± 2dB)
Maximum Input Power: 10W
Maximum Output Power: Input 5W, frequency <21MHz, power supply 15V = 100W
            Input 5W, frequency> 21MHz, power supply 15V = 70W

Low-pass Filter: Built-in 10, 15 and 17 meter band filters
Low-pass Filter Frequency: 33MHz (-6dB)
Harmonic Output: greater than -50db (even order), greater than -30dB (odd order)
Spurious Output Suppression: greater than 40dB
Input / Output Connector: SMA-K
Working Temperature: 0-50 ℃
Storage Temperature: -20-70 ℃
Storage Humidity: less than 55%
PTT Trigger Level: + VCC-2V (low trigger), GND + 5V (high trigger)
PTT Trigger Current: 2Ma
Product Size: 110 x 50 x 40mm | 4.33 x 1.97 x 1.57in
Product Weight: 230g | 0.51lb


1. Transmitting with an open circuit or short circuit will damage the amplifier.
2. Antenna standing wave ratio of under 2.5 to 1 is required
3. Maximum power input is 10 watts

Compatible Models:

Xiegu G90, Xiegu X5105

Available Accessories:

• 1. Radioddity LPFX7 low pass filter (plug and play | full-band low pass filter)

• 2. Radioddity LPMX2-1 & LPMX2-2 filter model DIY kits (need to be soldered by yourself)


1. This amplifier does not have an antenna tuner.
2. Hardwired connection for PTT is required for functioning.

Installation Guidance


Q & A:

Q: What is the difference on yours, yours is quite expensive I have seen similar amp going for cheaper on eBay.
A: It's a totally different product from what you saw on eBay or Alibaba. We made so many efforts to improve it. This version on eBay is not stable with only 50W sometimes and different performance for different radio (said compatible with many radios). We abandon the compatibility of ICOM and KW23.

What are the differences
1. Built-in 10, 15 and 17 meter band filters
2. Data adjustment for G90 & X5105 only (even not G1M)
3. Trigger cable/connector for G90 & X5105
4. Copper core feeder added
5. Plug and play for G90 & X5105, stable output
6. Circuit optimization
7. We improve some soldering parts for safety
All of the above have made its cost way more expensive than other versions you can see on eBay and Ali.

Q: Is soldering surface mount components needed? How long would it take to put together?
A: No, plug and play for PAX100 + LPFX7 + G90. If you've already had a DC power, 2 minutes.
If you prefer the filter model LPMX2 instead the LPFX7 with single-band filtering, you need to solder.

Q: Does the LPFX7 filter sit alongside the amp or does it fit inside the amp housing? If it goes alongside, do you include the cables needed to do all the connections? If I buy both, is anything missing that I need to connect it all?
A: It goes alongside. Both of them are with all the connectors and cables you need to install (except for the power plug). Refer to the following images to install. What you need is a DC power source.

Q: Is the power to the amp always on? Is there a switch?
A: For the amp, there is no power button. For the LPFX7 filter, it's with a power button, and 4 switches with LED to help you select the band you need.

User Manual:

Click Here to download.

What's in the box

1 x Radioddity PAX100
1 x Power Cable
1 x SMA to PL-259 adapter cable
1 x SMA to SQ-239 adapter cable (female)
1 x G90/X5105 PTT Trigger Cable
1 x Installation Guide

1 Year and 6 months
Manufacturer's Warranty.
• This warranty from Radioddity covers all new items (except Xiegu brand) purchased from For purchases made through other platforms like Amazon, eBay, and Walmart, we offer a 1-year warranty period from the date of purchase. The specific warranty terms may vary depending on the authorized dealer.
• This warranty cannot be transferred. You need to provide proof of purchase from us or an authorized dealer to avail warranty service.
• For Xiegu brand items, we offer a 1.5-year warranty for the G90, X6100, and X5105 models starting from September 14, 2022. All other models come with a 1-year warranty.

What Does This Limited Warranty Cover?

We warrant that the Products are free from defects in materials and workmanship under normal use and use in accordance with the respective Product user manual, during the Warranty Period. Please refer to the Instructions inside each package for a description of proper use and care of the unit.

What Does This Limited Warranty Not Cover?

This limited warranty does not cover damages directly or indirectly arising or resulting from or during:

(1) accident, misuse, abuse, vandalism or acts of God (including lightning and other weather conditions)

(2) use with another product or other damage or loss suffered by the use or combination of any other item

(3) improper or inadequate maintenance

(4) repairs by an unauthorized service technician

(5) normal wear and tear

Open Box

Open Box items are products that have damaged packaging or are otherwise not suitable to be sold as new. All items are tested to be working by a member of our team.

Open Box items come with a 6-month warranty instead of the standard 18 months warranty and are not eligible for any warranty extension offered to new products. We will not accept returns of Open Box items due to cosmetic damage or other non-performance-related issues. All sales of Open Box items are final and not eligible for a return or refund.

If for some reason the item is defective on arrival, please contact so we can arrange a replacement.

If you are satisfied with our products and service, please kindly leave us a positive product review. Any problem, be free to contact us
We strive to answer all emails as quickly as possible, but due to high email volume, it may take time for us to reply. Thanks in advance for your patience!

Order Processing

All orders are processed within 1-2 business days after we receive your full payment, excluding weekends and holidays.

As soon as your order is ready, we’ll update the tracking number and send it to you if you’re a Radioddity Member. We highly recommend that you register as a Radioddity Member here. If the item you ordered is temporarily out of stock, our customer service team will reach out to you. You can choose to wait until the item is back in stock or cancel your order.

Please be aware that we have several distribution centers globally. Therefore, your orders may be shipped from various locations including the United States, Canada, Europe, or China, depending on the availability of the product in our inventory.

Flat Shipping Rates




Outside US & EU

  Free when order amount ≥ $99.99 Free when order amount ≥ $99.99 Free when order amount ≥ $99.99

Flat fee




Ship from

➤ United States
➤ China

➤ Germany
➤ China

➤ China

Handling time 1-2 business days 1-2 business days 1-2 business days

Delivery time

5-7 business days

5-7 business days

7-15 business days


1. Customs fee included for US & EU countries.

2. Please note that taxes will be applied to shipping rates. These taxes will be calculated and added to your total at checkout.

3. US Shipping does not include Alaska, Hawaii and Puerto Rico area. Please contact us for a detailed shipping fee to these areas.

4. For EU countries, please be aware that the listed product prices do not include VAT.

5. For shipping options to other countries, please visit our EXPANDED INTERNATIONAL SHIPPING page.

6. Please be aware that for outlet items, pre-orders, and open box items, the shipping services and charges may vary.

How Do I Change The Shipping Address Or Cancel My Order

Contact (CLICK HERE) immediately if you need to change the shipping address or cancel your order. Please be advised that some orders are shipped very soon after placement and it will not always be possible to make changes to the shipping address and/or cancel the order.


Frequently Asked Questions

1. What forms of payment do you accept? currently accepts PayPal* or credit card for all orders.
*When purchasing with PayPal, your shipping address will automatically default to the address on file with PayPal, regardless of the shipping address you enter on your order.

2. Why has my credit card payment failed?
Payment with a credit card may fail because of bank authorization and fraud prevention systems. If you are having trouble making a payment via Credit Card, you may contact your card issuing bank or PayPal directly. Here are PayPal's phone numbers:
+1-888-221-1161 (US & Canada Toll Free) +1-888-215-5506 (US & Canada Toll Free)
+1-402-935-7733 (International) +1-402-935-2050 (International)

3. How do I know if it is safe to shop with you? takes great pride in offering a safe and secure online shopping experience. We also respect your privacy and we're committed to protecting it.

4. Is there any discount for bulk/volume purchases?
Radioddity does provide discounts for some bulk/volume purchases. Please email our customer service for more details.

5. Do you ship internationally?
Yes, we do! We ship to US & EU countries. For some products, we ship to CA.

6. How can I contact for additional assistance?
Email Customer service:
please email us via, and we will respond to your email as quickly as possible, usually within 24-48 hours.

7. How are warranties handled?
Repairs on defective merchandise are handled by the manufacturers and not by Radioddity unless otherwise indicated. If any item arrives damaged due to shipping, immediately contact the courier. Keep all shipping materials and contact us immediately.

8. Why didn't I receive an order confirmation email after my PayPal payment is completed?
We send a confirmation email to your primary PayPal email address or the e-mail address you have specified if you used the "PayPal Express Checkout" method. Make sure that you have a Radioddity account registered under your PayPal account's primary e-mail address.
In rare circumstances, a technical bug confirmed by PayPal can get in the way. If you do not receive any information at all, and your order does not appear in your Radioddity account, please contact us and send us your order details.

9. How do I change the shipping address or cancel my order?
Please contact customer service immediately if you need to change the shipping address or cancel your order. Please be advised that some orders are shipped very soon after payment and it will not always be possible to make changes to the shipping address and/or cancel the order.

10. What does charge for shipping order and how long will it be before I receive my order?
Please CLICK HERE to learn about our shipping policy.

11. Do you ship to PO boxes or Military APO/FPO addresses?
Only USPS can ship to both PO Boxes and Military APO/FPO addresses. The items have to be less than 2kg. Please allow additional time for orders to be shipped to these addresses. Express shipping cannot be sent to both PO Boxes and Military APO/FPO addresses.

12. Why am I unable to track my order?
It can sometimes take 24-48 hours or so for tracking information to update once an order has shipped from our warehouse.
Occasionally, a package may not receive the proper origin and transit scans while on its journey to you, so neither us nor express is able to track the exact location of the package in transit.
Please email us if you do not receive your order by the end of the quoted time frame. Please note that orders shipping via UPS can be delivered as late as 9:00 pm local time in some areas.

13. Taxes, Customs, & Duties
If the package is checked by your country's customs office when the item arrives in your country, most websites are declaring that you are responsible for import duties, tariffs, and taxes. However, Radioddity will be happy to go fifty-fifty with customers. Quality customer service is our highest value and we try our best to reduce our customer’s loss.

14. How do I return products if I am unsatisfied?
Please CLICK HERE to learn about our return policy.

15. What do I do if received the wrong item?
Return the wrong item. If the item you received is completely different from the one you ordered, please contact our Customer Service with photos or videos of the different product. If a return is necessary, replacement plus return shipping cost will be issued to you on receiving the returned product. Or if you decide to keep it, we will offer a 10% discount for buying it.

16. How do I return defective items?
If your product turns out to be a defective one with physical damage within 30 days from the initial receiving date. You can mail the item back in the original package without any wear and tear for a free replacement. However, you will need to provide photos and videos showing the defect(s) of the product.
*NOTE: We strongly recommend obtaining and saving your return tracking number until you are notified that we have completed your refund.*

17. When will a replacement be sent?
Replacements are treated the same way as that of new orders -- they typically arrive in 10 to 13 days. If a product needs to be returned for replacement, the replacement is sent after receiving the returned item.

18. How long does it take for me to get a refund?
It may take 1 or 2 weeks for your return to reach our warehouse. Once it is received and inspected (usually within 72 hours of arrival) your refund will be processed and automatically applied to your credit card or original method of payment within 2 days. Please note that depending on your credit card company, it may take additional 2-10 business days after your credit is applied for it to post to your account.