Tag Archives: LNR Precision

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.

eBay find: LNR Precision LD-11 transceiver

LD-11 eBay

Many thanks to SWLing Post contributor, Mario, who notes this first appearance of the LNR Precision LD-11 transceiver on eBay.

I must say, I’ve been using the LD-11 for the past couple of months and have been pleased–it’s a fun little radio with the added bonus of broadcast band reception (see my previous post). I’ve used it in no less than four NPOTA activations.

Mario and I do not know this eBay seller, but it appears the seller is in decent standing with eBay.  In the past 12 months, the seller has had one negative review that appears to have been in error (the comment in questions was very positive, but marked as negative by a new eBay user).  Do your research if you consider bidding.

Click here to view this LD-11 on eBay.

The new LNR Precision LD-11 transceiver is essentially general coverage

LNR-Precision-LD-11

A couple weeks ago, LNR Precision sent me their new LD-11 Digital Direct Conversion QRP transceiver on loan for review.

The LD-11 is basically a small, tabletop SDR transceiver. It’s like a miniature, simplified version of the Icom IC-7300 I’ve also been evaluating.

The LD-11 is an all-mode and all-band transceiver–meaning, it includes SSB, CW, CW-R, Digi, AM and FM modes on all amateur radio bands (160 – 10 meters).

Though the LD-11 isn’t advertised as having a general coverage receiver, it will indeed tune the entire HF band.

You do this by entering the LD-11’s administration mode. LNR describes this in the LD-11 product manual, but suggests you contact them for help the first time you do this. In the admin panel, you’ll find functions that allow you to set the band edges on each amateur radio band.

For a preliminary test of broadcast reception, I moved the lower band edge of the 30 meter ham radio band to 8.2 MHz.

LNR-Precision-LD-11-front panel

After saving the settings and re-starting the LD-11 in normal operation mode, I could then tune the entire 31 meter broadcast band on the LD-11.

Hypothetically, you could either widen each amateur radio band to include adjacent broadcast bands, or you could simply set one of the ham bands to include the entire HF spectrum. To make it easier to navigate and tune through the bands, I’m choosing the former method over the latter.

Since the LD-11 has a proper AM mode, broadcasts sound great–especially via headphones!

Proper AM filters for broadcast reception!

Better yet?  The AM filter width can be widened to an impressive 9.6 kHz! Woo hoo!

LNR-LD-11-Shortwave-AM

The LD-11 has four filter slots: F1, F2, F3 and F4.

The F1-F3 slots can be set to a fixed user-defined widths (common widths are default).

F4 can be altered to any available filter width without having to enter the admin mode of the transceiver. Simply press the “F” (blue function button) and the FILTER button simultaneously and use the encoder/tuning knob to specify the filter width in .1 kHz steps. Pressing the F and FILTER button simultaneously again, will save your filter width for the F4 position.

I’ve been using the F4 filter position for widths between about 8.2 and 9.6 kHz in AM.

It’s still early days with the LD-11, but I’m enjoying this little transceiver immensely. It reminds me of one of my favorite QRP transceivers of yesteryear: the Index Labs QRP Plus (though the LD-11 is much smaller, more versatile and has a much better front end than the QRP Plus!).

LNR Precision sold out all of their first run LD-11 units within moments of having announced availability. I’m willing to bet they’ll bring a few LD-11s to the upcoming Dayton Hamvention, though.

Check inventory status and view LD-11 details on LNR Precision’s website. 

LRN Precision introduces two new QRP transceivers: the LD-11 and MTR5B

LNR-MountainTopper-LD11-Announcement

LNR Precision announced two new QRP transceivers this weekend: the MTR5B and LD-11. Below, you can find details I pulled from LNR’s press release and website for both units:

LNR-Precision-LD-11

The LD-11

The LD-11 is a new 11-band QRP transceiver based on the LNR’s LD-5 transceiver. The LD-11 covers from the 6 meter band down to the 160 meter band. A new feature on this model is a built-in panadapter. AM/FM/SSB and CW modes are all included.

Here is the description from LNR’s website:

The new LD-11 is Digital Direct Conversion, SDR type, build-in CPU (SM32a) DSP radio in which RF signals are directly converted to a digital data via differential and balanced A/D converters. This enables direct sampling with extremely low phase and floor noise.

The DSP is unique and features two independent channels. It also employs a unique differential algorithm within the software which is applied for IQ processing of the channels with phase suppression of the unwanted side-band channel.

The balanced ADC and DAC gives additional noise floor reduction and the receiver can handle interfering signals that are 100 dB stronger than the desired signal at a frequency separation of 10 kHz, and is about 130 dB stronger at 50 kHz separation. As the receiver and transmitter are using the same DSP channel, there is no gap between the receiver performance and the transmitter performance. Thus, there is a clean neighborhood on the bands. At the development stage, our intentions were motivated by the TX side-band noise of existing SDR manufacturers, so our aim was to fully equalize our transmitter to have noise performance that is compatible with the best modern receivers, or even better. After a arduous year of development , we think we achieved it!

This 11+ band radio is based on the LD-5, which has proven to be one of the most exciting QRP transceivers introduced in the last few years. Quite frankly, the performance rivals high end units offered by other manufactures at a much lower price point. Our motto is that we make QRP transceivers that you will want to take out in the field (without fear of breaking the bank).

Price is $774.99 US

LNR-Precision-LD-11-L-Side LNR-Precision-LD-11-R-Side

Note: Larry Draughn (AE4LD), President of LNR Precision, will be issuing an LD-11 transceiver to me on loan for review. I’m looking forward to putting it on the air.

What fascinates me about the LD-11 is that, although it’s designed as a ham band-only transceiver, the band edges of the 30 meter ham band can be expanded to include the full 31 meter broadcast band. There are, perhaps, other ham bands that can include nearby broadcast bands as well.  I will plan to experiment with the band edges.

MTR5B

The MTR5B

The new MTR5B 5-Band Mountain Topper is a fully-assembled 5-band CW transceiver KD1JV designs “Steve Weber” kit. The following are specifications/features from the LNR website:

40M, 30M, 20M, 17M, 15M
Size: 4.337″L x 3.153″W x 1.008″T
Weight: approx 6.4 OZ.

Features:

  • Switch selected 40/30/20/17/15 meter bands (no band modules to lose or change out)
  • Wide operating voltage range, 6 to 12 volts 15 ma Rx current at 12V supply
  • Efficient transmitter. Low current with 4W output
  • LCD display
  • Push button or Optional rotary tuning
  • 24 hour clock built in, with battery back up
  • Three 63 character programmable message memories
  • Message beacon mode with adjustable pause time

MTR5B-1

Price is $379.99 US

Steve Weber’s QRP transceivers are amazing and incredibly portable. His MTR-3B trail radio has received very favorable reviews over the past year; I expect the same from the new MTR-5B.

If you were lucky enough to grab a first production unit of either of these radios, I would love to post your overview/review! I’m looking forward to checking out the LD-11 soon. I’ll post updates with the tag: LD-11

Portable antennas: a review of the Par Electronics EF-SWL

Last August and part of September, I traveled through the US with the CommRadio CR-1 and a couple of portable antennas: the Par Electronics EF-SWL and  NASA PA-30. I had the opportunity to try both in the field, and took notes as I used them. Following is a short review of the Par Electronics EF-SWL.

The EF-SWL ready to deploy.

The EF-SWL ready to deploy.

Par Electronics EF-SWL 

At the Dayton Hamvention last year, I had the pleasure of speaking with representatives of the North Carolina-based LNR Precision Inc. LNR is a mom-and-pop company with a focus on providing antennas, keys, and transceivers for the ham radio and shortwave listener markets.  Indeed I have several SWL friends who use on a daily basis an antenna this company manufactures and retails: the Par Electronics EF-SWL. LNR asked if I would consider reviewing their antenna, and since I was planning a road trip with radios in tow–the perfect opportunity to test such an antenna–I agreed.

The Par Electronics EF-SWL is an end-fed shortwave antenna designed for 1-30 MHz reception. It’s a receive only-antenna–perfect for the SWL. The radiator is 45 feet of #14 black polyethylene coated Flex-Weave wire. When I first used the EF-SWL, I noted the quality of its construction: no doubt it can withstand many deployments in all weather conditions–and it’s manufactured here in the US.

With a 45′ radiator, the EF-SWL needs a little space, but offers more gain than the other portable antenna I packed, the NASA PA-30 (look for its review in the near future). I put the EF-SWL to use in New Mexico where several large trees were readily available. I hooked the EF-SWL up to the CommRadio CR-1 and simply hung the end of the radiator as high as I could in a nearby tree. Though not a picture-perfect installation, it nonetheless certainly did the trick! I didn’t bother with a ground connection as I wasn’t in an area with much radio noise (RFI).

In the past, when setting up portable ham radio and shortwave listening, I’ve typically built my own antenna either for the specific meter band I hoped to use, or brought along a portable antenna tuner. It was quite nice having an antenna designed to be resonant on the broadcast bands.

Par-EF-SWL

Though I didn’t do this, I did noticed that the EF-SWL’s radiator is attached via a stainless stud–Par Electronics did this so you can remove the radiator and replace it with a different wire length. With the stock 45′ radiator, I still find the EF-SWL quite portable, especially when compared with most of the portable amateur radio antennas I use, which tend to take a dipole or delta loop configuration.

After returning from my trip, I decided to hook up the EF-SWL at my home base for longer-term evaluation. These past months I’ve had it on the air as an auxiliary antenna, and I’ve been impressed with its performance. In truth, it’s not in an optimal location hanging off the corner of my house, but I think this may actually represent with some accuracy the installation most SWLs will likewise be able to provide–in other words, placement that must factor in antenna restrictions or limited space. Of course, for any permanent installation, you will need to ground the EF-SWL for lower noise reception.

And yet, even in these suboptimal conditions, the antenna performs remarkably well.

As with any exterior antenna, of course, take precautions against lightening if you live in an area with thunder storms. If nothing else, at least disconnect the antenna when not in use.

Moving forward, I will plan to relocate the EF-SWL to a more ideal permanent location and most likely purchase another to keep in my antenna bag. I hope to use this antenna in a DXpedition I’ve planned later this year.

The EF-SWL retails for $75 US directly from LNR Pecision or $72 US from Universal Radio.

Note that LNR also sells a number of QRP field-portable transceivers: the LD-5, FX-4a and Mountain TopperClick here for more details.