Many thanks to Philip (KA4KOE) for the following guest post:

Review of the FX-4CR Mini-Transceiver: What’s Old is New Again.

by Philip (KA4KOE)

Introduction

My start in Amateur Radio began in 1979 as a newly-minted, 16 year-old Novice. At the time, my resources were slim. I worked in a country store; pushing a broom, putting up stock, bagging groceries, etc. I was paid $23.46 every two weeks. At this time, Heathkit was selling kits to the ham radio community that ran the gamut from simple to elaborate. Looking over the catalog, my young eyes were drawn to the HW-8. What drew my attention was not the radio’s features, but the price.

The Heathkit HW-8 was listed for $129.95, plus shipping. I did not even notice that the power output was specified at 3.5 watts on 80 meters. The green gem was a bonafide ham radio transceiver!

In due course, the kit was acquired, assembled, tested, and put on the air with an Elmer’s aid. I made a bunch of contacts with that CW-only transceiver. The term “QRP” never entered my mind. I don’t have any photographs from my early days on the air: the only photograph of the HW-8 dates from 1981 during my freshman year of college. By that time, I had acquired an HW-100 from a fellow ham. See Photograph No. 1: note the chrome Vibroplex Lightning Bug, homebrew “T” network transmatch, and of the course the ‘8 on far right (see red arrow).

Photograph No. 2: Heathkit HW-8. (Image Source: WD8RIF)

Rationale and the radio

Without getting into my entire life’s story, I will start this paragraph by stating that my ham “career” has now come full circle as I’m back to using compact, lightweight, low power gear; this time by choice.

I had the bad habit of deploying too much gear during POTA activations. I came across internet chatter with regards to a relatively new product; the FX-4CR SDR mini-transceiver. The base specifications are as follows:

Dimensions: 107mm (4.2”) L x 65mm (2.6”) W x 43mm (1.7”) H.
Weight: 0.46 KG (1 LB).
Bands/Power: 80 meters thru 10 meters, inclusive: 20 watts. 6 Meters: 5 watts.
Display and Panadapter Span: 50mm (2.0”) TFT, Approximately 24 KHz +/- (48 KHz total) and waterfall. See Photograph No. 3.
Modes: LSB, USB, CW, FM, AM, Digital.
Receive Current Draw: 210 mA.
Transmit Current Draw: 3.0A to 4.0A at full rated 20W output.
Input Voltage Range: 9 VDC thru 16 VDC (do not exceed). The optimal supply voltage is 14 VDC.
Connectivity: Bluetooth for CAT/Audio. USB Port for CAT/Audio and Firmware Updates. Integral audio soundcard input/output.
Output Power: Continuously variable from 0.1 thru 20W. Recommended maximum wattages are SSB – 20W, CW and Digital – 10W.
No internal battery or antenna matching unit.

Photograph No. 2: My FX-4CR, 6 AH Bioenno LFP, Genasun GV-5.

Expectations

The prospective buyer should realize what this radio “brings to the table”. As others have previously stated on the various internet chat groups and social media, do not expect Elecraft performance at the $550 (including shipping) price point for this radio. All radios have flaws and this one is no exception. Issues of which I am aware are as follows: Continue reading KA4KOE takes a look at the FX-4CR by BG2FX →

This year, I’ve had a couple of readers very kindly offer to loan me their FX-4C transceivers to take to the field and review.

Those offers have been very temping because I’ve only heard positive comments from owners of this wee feature-packed SDR transceiver designed by Yu (BG2FX).

Earlier this year, I learned that Yu was retiring the FX-4C and would be introducing two new radios, so I decided to hold off on an FX-4C review for this reason.

My buddy, Don, informed me that the new radios were now available for pre-order, so I checked out the option on Yu’s website, and placed an order.

Details (features and specs) are still a little sparse because BG2FX is still finalizing the design and lining up production, but here’s a snapshot of the two models based on Yu’s preliminary info:

The FX-4CR

I was very pleased to read that my buddy John (AE5X) has one of these on order.

The FX-4CR can push 15-20 watts on most bands according to John, which is most impressive for a one pound radio that fits in the palm of your hand! It covers 80 – 6 meters, sports a color screen with a 48 kHz wide waterfall display, an internal sound card for digital modes, built-in speaker and microphone, 9 – 18 VDC input range, and even sports Bluetooth!

That’s an impressive array of features for $550 US (on pre-order).

The FX-4L

I pre-ordered the FX-4L and am told by Yu that it should ship by end of October or early November 2022. I wouldn’t be surprised if that’s an optimistic projection.

The FX-4L is essentially a more basic QRP version of the FX-4CR; it’s maximum output power is around 5 watts.

It’s very similar to the FX-4CR in many respects: it has the same display from what I can tell, covers 80 – 6 meters, has a wide voltage range 9 – 18 VDC, sports an internal sound card, and is super compact and lightweight.

The FX-4L doesn’t appear to have Bluetooth. Lu doesn’t mention a built-in speaker or microphone, but there’s an obvious speaker grill and even a small hole that might be a microphone. I’ll try to confirm this. Yu does note that there’s room in the chassis for the user to add a battery or ATU.