Tag Archives: Elecraft KX2 AM Mode

AM Mode: Comparing the Elecraft KX2 with the LNR Precision LD-11

My new Elecraft KX2 tuned to Radio Australia this morning.

My new Elecraft KX2 tuned to Radio Australia this morning.

I’ve only had my Elecraft KX2 since Monday evening and have been so busy, I’ve only had an hour or so to tinker with this pocket transceiver. Monday evening, before putting it on the air, I updated the KX2 firmware to the latest Beta release which includes the new AM mode.

I’ve had so many questions from readers about the KX2’s AM audio already, I thought I’d do a quick comparison with the LNR Precision LD-11.

I set the LD-11 to a bandwidth of 9.6 kHz, and the KX2 to 5 kHz: their widest AM filter settings. Keep in mind, this is not an apples-to-apples comparison, but it does showcase each radio’s potential AM audio fidelity.

I tuned both rigs to the Voice of Greece last night on 9420 kHz around 00:30 UTC. VOG’s signal was strong into North America.

I made the following recordings with my Zoom H2N digital recorder, by feeding in-line audio patched from each radio’s headphone jack. I tried to balance the audio levels between the two rigs.

Here are the results:

The LNR Precision LD-11

LNR-Precision-LD-11-AM-Mode-Voice-Of-Greece

Click here to download the audio.

The Elecraft KX2

Elecraft-KX2-Voice-Of-Greece-AM-Mode

Click here to download the audio.

The Elecraft KX2 in “Delay” audio mode

Note: Some Elecraft radios have an audio effects mode which includes a “delay” function. Elecraft describes it as “a quasi-stereo effect intended to provide depth and space to the received audio.” On an AM broadcast signal, it makes it sound wider and gives it almost a stereo depth.

Elecraft-KX2-Delay-Audio-AM-Mode

Click here to download the audio.

I think the results from both radios are impressive. Since the LD-11’s bandwidth can be widened to 9.6 kHz, strong signals like this one sound pretty amazing. In truth, I actually prefer a filter width of about 8.2 kHz on strong signals, but VOG was wide enough to justify 9.6 kHz.  I believe the LD-11 would rival many dedicated tabletop receivers.

The Elecraft KX2, in normal audio mode, sounds flatter and narrower than the LD-11 of course, but still very pleasant!  In the KX2’s “delay” audio mode, the signal sounds much wider than 5 kHz, though the effect adds a little graininess to the audio. That’s okay, though–I love having the “delay” audio option in my tool bag.

Here’s what amazes me as an SWL and ham radio operator: both of these QRP transceivers offer excellent HF broadcast listening opportunities.

Please comment! Which audio sample do you prefer? Do you like the “delay” audio effect on the KX2? Keep in mind this is only one comparison and doesn’t address sensitivity or selectivity.

John takes the Elecraft KX2 on the shortwaves

ElecraftKX2

I just noticed that John (AE5X) has updated the firmware on his KX2 and made a short video of a shortwave band scan. On his blog, he notes:

Before getting my ham ticket, I was a SWL and am very happy that AM capability has been added to the KX2, making a fantastic radio even better.

[…]We have a very powerful AM broadcast station near my QTH on 740 kHz. I was not able to receive it at all with the KX2. Unlike some, I see this as beneficial – it tells me the 80m filters (the KX2 doesn’t operate on 160m) are doing what they were designed to do.[…]

Read the full post on John’s excellent blog.

Click here to view John’s video on YouTube.

Update: I’ve had my KX2 for 24 hours now! I’ve already updated the firmware and will post a couple AM audio samples soon.

Video: Elecraft KX2 daytime shortwave AM performance

ElecraftKX2

After publishing the post this morning regarding the AM mode addition to the Elecraft KX2, SWLing Post contributor Ivan Cholakov (NO2CW) created the following video comparing the KX2’s daytime shortwave reception with that of the Kenwood R-2000:

Click here to view on YouTube.

The Elecraft KX2 now has AM mode!

Elecraft-KX2-6

The Elecraft KX2 at the 2016 Hamvention

Many thanks to a number of SWLing Post readers (including, Eric, Dave, Jim and Greg) who shared the following message from Wayne (N6KR) on the Elecraft message boards:

We added AM mode to the KX2 today, both transmit and receive. Its primary purpose is for SWL (short-wave listening), i.e. copying commercial AM stations. (Remember that the KX2’s sensitivity drops off rapidly below 2 MHz due to protective high-pass filtering, so it wouldn’t be your first choice for AM brodcast-band DXing.)

AM transmit is far less efficient than SSB, so it would typically be used only if the target receiver can’t demodulate SSB, or for special applications. For example, there’s some AM activity and experimentation in the ham bands, notably around 3.870 kHz at night. I’ll have to drop in with 10 watts (carrier + sidebands) and get a report 🙂

While the KX2 was optimized for SSB, AM mode sounds fine, and of course is easier to tune than when using SSB modes with AM. In AM mode, the operator can select 1, 5, 9, or 10 kHz steps for course tuning using the VFO CRS menu entry. (Yes, some countries use 9 kHz intervals between stations.)

If you’re interested in testing AM mode on the KX2, please email me directly.

73,
Wayne
N6KR

On Sunday, I ordered a KX2 (with ATU, rechargeable battery pack, quick charger and paddles)–it should arrive next Monday. First thing I’ll do is upgrade the firmware so it’ll have AM mode.

Many thanks to Wayne (N6KR) for putting this KX2 upgrade at the front of the (long) line of requests.  I’ll be reviewing the KX2 for the November issue of The Spectrum Monitor magazine and, as an avid SWL, AM mode adds an important dimension to my evaluation. (Truth is, I know that Wayne has a soft spot for SWLing too.)

Elecraft-KX2-Data-SheetClick here for a previous post with more information and photos of the Elecraft KX2.

Click here to view the KX2 on Elecraft’s website.