BITX40 on the air

Several months ago I purchased a BITX40 in anticipation of time off for the holiday season. I like to have some projects in the queue for the time of rest and relaxation over Christmas and New Year’s where rest and relaxation means packing as much Amateur Radio into the time allotted. Building, operating, repairing, you name it. For the past number of years my log always indicates a dramatic spike in activity through November and December.

I’m a regular listener to the Solder Smoke podcast. Bill, N2CQR and Pete, N6QW talk about the BITX40 a lot and so I decided to purchase one. The BITX40 was developed and is built by Ashhar Farhan, VU2ESE in India. It is a very popular SSB QRP radio that has a good-sized following including numerous mods.

Despite the onset of a cold\flu just in time for vacation, the solder must melt. To be fair, there isn’t a whole lot of melting solder involved as building a BITX40 consists largely of final assembly, making all of the connections between the I\O components and the the two boards.

The BITX ships really quickly from India. Mine arrived packed in a cardboard box in a DHL shipping pack about a week after I placed the order.


The components of the BITX40 are contained in a nice plastic box:

BITX40 container

The BITX40 consists of the following components:

BITX40 components

The primary components being the BITX40 and Raduino boards, already assembled. As I said, building a BITX40 consists of final assembly. Farhan, VU2ESE provides a good set of instructions for wiring up the BIT40 on his site here.

The BITX40 doesn’t come with an enclosure nor is one available from Farhan, VU2ESE. This has lead to a number of creative packaging solutions from standoffs on a wooden board to this very nicely crafted homemade enclosure built by Mike, AB1YK. I was sorely tempted by Mike’s approach but chose to purchase an enclosure. I waited too long to order the enclosure and it hasn’t arrived yet, so I decided to build this in benchtop spaghetti mode.

BITX40 benchtop spaghetti build

Assembly took maybe an hour, working to minimize any magic smoke releases. I chose to connect the audio output directly to a 3 inch, 8 ohm speaker for the initial test as opposed to using the supplied jack. Once assembly was complete I hooked it up to an old Clegg Model 011 power supply and my Hustler 4BTV. I used the supplied mic and PTT button, both of which are quite tiny:

BITX40 mic and PTT

Given the progress (regress?) of my cold\flu over the last few days, by late this morning I thought that I would be relegated to one of the laryngitis modes, CW or digital. for any radio operations. But by late in the afternoon I had enough voice to squeak out the BITX40’s inaugural contact. After an uneventful power-up I started to tune across the 40m band. It was late in the afternoon (1600 CST) and there were a number of strong signals and some weaker ones across the band. I was really amazed at how well the BITX40 sounded. It has very nice, very clear audio. Tuning is accomplished with a single-turn 10K linear pot. Initially I thought this would be the first thing to change, expecting to substitute a 10-turn pot, but it tunes really well with the single-turn unit. After reading the mail on a few QSO’s where both sides had strong, clear signals I came across a QSO between N0JQX in Salem, MO and W2HDI in Stowe, VT on 7.165. I could hear both stations very well. As W2DHI signed, I gave Al, N0JQX a call. His initial response was “KA9” station calling, but he didn’t have my suffix. After a couple more tries Al had my full call and we we’re able to have a short but nice QSO as the band shifted around us. N0JQX was 59 here (with no S-meter) and he gave me a 54-55. This with 7 watts and some patience on Al N0JQX’s part.

Band conditions at the time

The next step is to install this thing in the enclosure once it arrives. At that time I’ll tidy up the spaghetti and change to a proper hand mic. We’ll see where it goes from there. This thing is going to be a lot of fun.

The BITX40 would make a very nice intro radio. It’s not difficult to assemble and appears to perform well. With a host of mods and a community of support it should appeal to many new operators. Plus, Farhan, VU2ESE has recently released the µBITX which is multi-band (3 MHz to 30 MHz), and dual mode with 10 watts on SSB and CW. It’s entirely likely that I’ll have to add one of these to my station at some point.

UPDATE 12/29/17

The enclosure arrived today.

BITX40 enclosure

It’s very nice. Heavier gauge than I expected. About 22 gauge. I got it off eBay from a seller in Hong Kong. $22.99 with “free” shipping. It’s probably a smidgen larger than needed but it will leave some room for any future mods. Plus, I’ve never had an orange radio.


2 responses to “BITX40 on the air

  1. I hope to put my uBITX on the air next weekend and a good report on a BITX40 makes me a bit more confident. There’s a part of me that says a $109 radio won’t do what they say it will…

    • We’ll probably know soon. It appears as if they have already shipped over 1000 MBITX kits. I recently subscribed to the BITX group on Groups.IO ( There’s a fair amount of chatter, some works right the first times, and people are apparently already working on mods for the firmware. My guess is that if it has some issues that Farhan, Vu2ESE will make it right.

      As I said, I am reasonably impressed with how well my BITX40 works. My expectations were low. I knew it would work but just not as well as it has thus far. In my view, it performs better than I expected for a $59 radio. Granted the MBITX is another $50 so hopefully it performs as well.



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