Category Archives: SOTA

A review of the Par EndFedz EFT-MTR triband antenna

Note: the following post originally appeared on our sister site, the SWLing Post.

The Par EndFedz EFT-MTR triband (40/30/20M) antenna

In July, I purchased a tiny QRP transceiver I’ve always wanted: the LnR Precision MTR-3B. It’s a genius, purpose-built little radio and a lot of fun to operate in the field.

It’s also rather bare-bones, only including a specific feature set built around ultra-portable CW operation.

While the MTR-3B has features like CW memory keying, a wide operating voltage (6-12 VDC), extremely low operating current (20 ma in receive), real-time 24 hour clock, and a full compliment of keying adjustments, it lacks other features like a volume control, SWR meter, speaker, and built-in antenna tuner.

Some of those may seem like big omissions but SOTA and POTA activators who like extremely lightweight/portable gear love the MTR-3B for being so purpose-built.

The MTR-3B (and its predecessors) operate on three bands: 40, 30, and 20 meters. These are, without a doubt, my favorite bands when operating portable since antenna lengths are reasonable.

Since the MTR-3B doesn’t have an internal ATU, you need to pack an external tuner or, better yet, a resonant antenna–ideally, one that can be used on all three bands.

Although many of my portable transceivers have built-in ATUs, I rarely use them because I primarily operate with resonant antennas. Resonant antennas are more efficient–giving you the maximum mileage per watt. In addition, they’re also more simple: connect them to the rig and hop on the air. No tuner or tuning required.

Since I keep self-contained field radio kits, my MTR-3B needed a dedicated resonant antenna.

The EFT Trail-Friendly antenna is incredibly compact and quite easy to deploy.

I’ve mentioned in previous posts that I’m a big fan of the Par EndFedz Trail-friendly EFT tri-band antenna (above) which is resonant on 40, 20, and 10 meters.  I’ve activated well over 130 parks with this little antenna.

After I took delivery of the MTR-3B, I borrowed the Trail-friendly EFT antenna from my KX2 field kit. It worked well on 40 and 20 meters, but it doesn’t cover the 30 meter band. Also, by borrowing the EFT from the KX2 kit, I broke one of my rules: never borrow from one field kit to feed another. This led to me leaving the EFT hanging in a tree at a remote park and returning a week later–a three hour round-trip(!!!)–to retrieve it. (FYI, in all fairness, I also blamed my trusty canine companion for this mishap!)

Enter the Par EndFedz EFT-MTR triband antenna

A few months ago, Vibroplex purchased the Par antenna line from LnR Precision.

I was very pleased with this decision as I’m guessing LnR Precision wanted to hand off antenna production so they could focus on the very popular Mountain Topper transceiver line.

Vibroplex is owned by my buddy, Scott Robbins (W4PA), who is not only a successful entrepreneur, but also an award-winning contester and DXer. I’ve known Scott for years and knew he’d not only be a great steward of the Par product line, but also push new innovations.

I emailed Scott asking if Vibroplex had a field-portable antenna that would be resonant on 40, 30, and 20 meters. Turns out, there’s a Par antenna designed specifically to pair with the MTR-3 series transceivers: the Par EndFedz EFT-MTR.

Scott pointed me to a description of the antenna on the Vibroplex website:

The new EndFedz ® EFT-MTR is a 40m/30m/20m tri-band QRP antenna rated up to 25 watts. The “MTR” name was selected as LNR Precision developed this antenna to be the perfect companion to the wildly popular 40/30/20m Mountain Topper QRP transceiver. The EFT-MTR’s total length is 65′ of 22 AWG polystealth wire and weighs less than 4 ounces! It is built with the same high level of workmanship and quality that you have come to expect with all EndFedz ® antennas.

A particular innovation on this antenna: This EndFedz is a little different than previous designs. The user has the option to remove an SMA connector at the end of the 30M resonator to enable just 30 meters, or keep the SMA installed for 40 and 20 meters. Because of the broad bandwidth of the antenna, it is unlikely that it will require tuning in the vast majority of deployments. This is particularly true of 30 meters where the band is very narrow. As our tagline states, “They Just Work!”

Included with the EFT-MTR is the EndFedz Antenna Winder. Conveniently allowing winding up the antenna line to not have a tangled mess at the end. The winder will hold both the antenna and 25 feet of RG-174U coaxial cable (optional accessory).

Scott offered to send me an EFT-MTR to evaluate in the field (disclaimer: at no cost to me) and I accepted without hesitation, of course!

An EFT-MTR field review

I’ve taken the EFT-MTR antenna to three park activations at this point and have formed some opinions about it.

The EFT-MTR fits perfectly in a slide-in pocket in the main compartment of the Boot Boss.

First of all, I couldn’t be more pleased with the size as it fits perfectly in my MTR-3B field kit built around my Red Oxx Booty Boss pack.

I really like the built-in antenna winder: it’s larger than that of the EFT Trail-Friendly, but also much easier to wind up and manage post-activation.

I’ll admit, the length of the EFT-MTR was a bit surprising the first time I deployed it: 65 feet.  Keep in mind, though, I had been used to a much shorter 41 foot radiator on the EFT Trail-friendly. Occasionally, I operate in spots where I simply don’t have the room to deploy a long antenna. I also worried that the EFT-MTR resonance might be negatively affected by winding its way through trees and over a branches. The MTR-3B transceiver does not like high SWR values and has no built-in SWR meter to monitor it. Last thing I wanted to do was harm the MTR finals.

You might be able to spot the feed point of the EFT-MTR at my activation of K-6952 this week.

Fortunately, winding its way through trees doesn’t seem to have a significant impact on SWR.

Each time I’ve taken the EFT-MTR to the field, I’ve also taken my KX2 which I’ve used to read the antenna’s SWR value. So far, the difference has only been negligible and SWR well within the tolerances of the MTR-3B.  Score!

I should note here that since I’ve started using an arborist throw line, I’m also able to hang antennas much higher than I could before. This has had a huge impact on all of my field activities.

Removing the SMA cap changes the EFT-MTR from a 40/20 to a 30 meter resonant antenna.

To be resonant on 40, 20 and 30 meters, the EFT-MTR requires a field modification. On the coil about 2/3 the way up the antenna, there’s an SMA connector with a small screw on cap (see above). When the cap is on (thus completing the connection) the antenna is resonant on 40 and 20 meters. You must remove the cap for it to be resonant on 30 meters.

Since I’ve been using the EFT-MTR, I start an activation on 40 meters (which is typically my most productive band), then move to 20 meters (typically, my least productive). If I have the time, or need the extra contacts to confirm a valid activation, I lower the antenna, unscrew the SMA cap, and raise the antenna again.

I thought at first this would be a major pain, but it hasn’t. Now that I’m using an arborist throw line, it’s super easy to lower and raise antennas. But even when I’ve used fishing line, it really hasn’t been an issue.

The only issue I see is I’m afraid I’m going to lose that little SMA cap in the field. To prevent this, I’ve made it a routine to immediately put it in the internal zippered compartment of the Booty Boss pack. I might find a source for those caps, though, just in case I still lose this one.

I’ve been very pleased with the EFT-MTR’s performance. I’m guessing it’s actually higher gain than my beloved EFT Trail-Friendly antenna. On my last activation with the EFT-MTR, I knocked out eight 40 meter contacts in about eight minutes during a period of poor propagation. Note that the MTR-3B was only pushing 3 or 4 watts of power.

I then moved to 20 meters where, frankly, propagation was so crappy I didn’t hang out there long. Instead, I lowered the antenna, removed the SMA cap, and started calling on 30 meters. Within a few minutes, I racked up the rest of my contacts.

I was very pleased with how quickly the Reverse Beacon Network picked up my CQs and was thus auto-spotted on the POTA website.

Conclusion?

If you own a Mountain Topper MTR-3 series transceiver, I highly recommend the EFT-MTR antenna. As with my EFT Trail-friendly and Par sloper, the quality is top-shelf. I expect the EFT-MTR will last even longer than the EFT Trail-friendly since the winder is so accommodating and the in-line coil is designed so that it doesn’t snag on branches as easily.

I’m looking forward to much more field fun with the MTR-3B and EFT-MTR combo!

Click here to check out the EFT-MTR at Vibroplex.

Click here to check out Vibroplex’s full line of antennas.

Many thanks again to Scott at Vibroplex for sending me the EFT-MTR for evaluation!

New Product: Kev-Flex Stealth Kevlar Antenna Wire

My good friend David Cripe (NMOS) has recently informed me about a new product he’s offering to the radio community via his eBay store: Kev-Flex Stealth Kevlar Antenna Wire. Kev-Flex looks like a superb option for field antennas of all stripes especially since it has an incredibly high tensile strength. It’s available in 75′ bundles, but Dave can also cut custom lengths. NM0S is also a trusted retailer in the ham radio world, so you can purchase with confidence.

Here’s the product description and link:

Kev-Flex is a unique antenna wire manufactured exclusively for NM0S Electronics. The lightweight center core of the wire is made from Kevlar fiber, giving the wire its incredible strength. The Kevlar core is wrapped with six tinned strands of 30 AWG copper. The effective surface of the wire creates an effective skin area capable of handling well over 100W.

The cable is protected from the elements by a coating of UV-resistant black polyethylene. With a total diameter of only 1/16″ (incl. insulation) and a weight of just 16 feet per ounce, the tensile strength 125 lbs allows lengthy unsupported horizontal runs. Kev-Flex is ideal for extremely long LW-antennas and Beverages and is great for balloon or kite-supported antennas. Its low weight and high break-load makes it most suitable for SOTA activations and other field operations.

The outer insulation makes the wire kink-resistant, and its slippery finish makes it ideal for stealth antennas that must be passed through trees or other obstacles without snagging.

This antenna wire is sold in 75 foot long bundles, which is enough for a 40M dipole or EFHW. Two 75 foot bundles would make a great 80M dipole. Custom lengths are available on request.

Specification

– Kevlar fiber core wrapped with six 30 AWG copper strands
– Weather-proof black polyethylene (PE) insulation, 1/16″ O.D.
– Weight: 16 feet per ounce
– Breaking-load: 125 lbs
– Velocity factor 0.97

Click here to view on eBay.

Ham takes SOTA activation to new level

(Source: Southgate ARC)

Amateur takes unusual route to SOTA

Colin Evans, M1BUU, from near Haworth, West Yorkshire attained SOTA Mountain Goat on Saturday 28th January on the summit of Whernside, G/NP-004.

Colin took rather an unusual approach to his activation of Yorkshire’s highest mountain, by constructing his equipment whilst on the summit.

Colin had taken a QRPme 20m RockMite kit, a home made key kit, a home made vertical antenna kit and a gas powered soldering iron along with him. Sheltering from the wind, rain and snow in a small tent, Colin successfully constructed the RockMite, key and antenna in just under 4 hours.

The first QSO for Colin with his 250mW RockMite was with N1EU near Albany, New York, over 3000 miles away, the three subsequent QSO’s were with European stations, satisfying the SOTA rule requirement of four QSO’s to claim the activation points.

SOTA Mountain Goat is awarded for gaining 1000 SOTA Activator points. For more information, visit www.sota.org.uk

Mountain Topper Radio review by G0POT

MountainTopperRadio-MTR-Via-LNR-Precision

(Source: Southgate ARC)

Michael Sansom G0POT has released a video review of the LNR Precision version of the MTR, Mountain Topper Radio, a three band, CW only, QRP trail friendly transceiver

Watch Michael’s Mountain Topper Radio review below:

G0POT https://twitter.com/DrOrthogonal

Adam’s Yaesu FT-817ND Go Kit

Adam (KJ6HOT) writes:

“Just wanted to pass on a link to a few videos I put
together in case you’d like to share them, especially the Yaesu
FT-817ND kit I put together.”

Adam has also posted some SOTA activation videos where he uses his go kit (click here to watch).  I’m amazed that Adam manages to fit so much in that small box. Certainly a handy kit for hiking to a SOTA activation!

Thanks for sharing, Adam! I’ll add this link to our Going Portable page. If you have a portable set-up you would like to share, please contact me.

SOTAbeams new line of radio stands

KX3-StandMany thanks to Graham (G3ZOD) for this tip:

SOTAbeams (UK) has a new range of perspex stands for popular QRP CW radios.

These include personalized ones with callsign for K1, KX3, FT817, and X1M, and a non-personalized one for KX1, HB-1B, and R4020.

Click here to view SOTAbeam’s range of radio stands.

This Sunday: the first annual SYBO QRP contest

hot-sun-thermometerThis Sunday (July 14, 2013) from 16:00-22:00 UTC, grab your QRP rig and head for the outdoors in the new SYBO (Scorch Your Butt Off) contest. According to the SYBO website, this contest is all about operating in hot weather conditions (something very easy to find this year in North America); a nice contrast to the FYBO (Freeze Your Butt Off) winter QRP contest.

Basic rules and exchange are as follows:

(Source: SYBO)

Scorch Your Butt Off QRP contest
SUNDAY, July 14, 2013 1600-2200 UTC
Categories –

  • Single Op Field or home
  • Multi Single Field or home
  • Multi Multi Field or home
  • SOTA – Summits On The Air Field (not the house roof)

QRP 5 watts max CW around QRP calling frequencies 10, 15, 20 and 40 meters
One point per contact – one contact with each station per band

Exchange –
RST, SPC (State, Province or Country), Name, Power, Temperature (Fahrenheit)
at the operator’s position. Indoor stations must report Indoor temperature.
Example – 559, NJ, Larry, 5W, 85F

Multipliers –
States, Provinces and DXCC count once each band
Field Stations x 4
Alternative Power (including batteries) x 2
QRPp (less than 1W) x 2
SOTA stations – add 100 points* to their SYBO score per summit activated
* Bonus points do not count towards SOTA awards

Highest Operating Temperature (at your operating location –

Below 90 F = x1; Cool weather

90 – 99 F = x2; Break out that Hawaiian shirt

100 – 104 F = x3; Just starting to warm the rattlesnakes up

105 – 109 F = x4; BBQ weather

110 – 114 F = x5; A nice sauna temperature

115F and UP = x6. Am I smelling bacon frying?

Outdoor ops use this Heat Index.

Rules and directions for submitting your results can be found on the SYBO website.

Have fun! Please stay safe and hydrated in this summer QRP contest!

Thursday SOTA: QRP DX from the Jura Mountains

The Juras are located north of the western Alps, predominantly in France. (Photo: Wikimedia Commons)
The Juras are located north of the western Alps, predominantly in France. (Photo: Wikimedia Commons)

I just received this message from Olivier Parriaux (F4GLD):

This supply is ready!

This Thursday [09 May 2013] we will activate, if time permits, the beautiful summit of Cret de gout which is located in the Jura mountains in JN26WD.

F/JU-004 – Cret de la Goutte Locator JN26wd
46.15140 ° N (46 ° 9 ‘5.0 “N) Longitude 5.86560 ° E (5 ° 51’ 56.2” E) 1621 meters, 5318 feet

Scheduled departure was 0300 TU [UTC] you should be able to follow the ascent via APRS.

We use + or – frequency QRP only Phone on 7/14/21/28 MHz bands depending on the propagation and F4OQU F4GLD Olivier Gilles.

HF Station KX3 5W max, Buddistick antenna, battery and three …
We also try to activate UHF
VHF F0FNC Laurent around 144,290 in SSB.
FT-817 5w max, DK7ZB antenna
We planned things on the air from 5h30/6h30 TU [UTC]

Hoping to see you on the air on Thursday.

73’s to all.

Like Olivier, if you’re planning a SOTA or QRP DXpedition of any stripe, contact me and I’ll be happy to post your announcement here on QRPer.

SOTA at the Charlotte Hamfest, Saturday March 9th

SOTAIf you’re planning to attend the Charlotte, NC hamfest (March 8th and 9th), make a point to join the SOTA (Summits On The Air) forum.  Christian (KF4LXB), provided me with details:

The forum itself is from 11:45am-12:45pm [Saturday March 9th] in the Cabarrus Room B. There will be total of five of us “SOTAteers” KF4LXB, W4ZV, KI4SVM, WH6LE, and W4ZTM with our kits. We hope to be able to set up a table outside of the conference room so we can have some extra “show and tell” time with our rigs for those interested. We want to get the word out to as many people as possible so we can share about something we all love.

Forum page: http://www.w4bfb.org/hamfest2013/forum_sota_webpage.html

Hamfest site: http://www.w4bfb.org/hamfest2013/hamfest.html

SOTA is serious QRP fun. Thanks for sharing this, Christian!

If you have a QRP related event you would like to publicize, simply contact me with the details and I would be happy to post it on QRPer.com.