Tag Archives: Portable Speakers

Any advice on compact Lipo batteries, in-ear earphones with volume control, and portable amplified speakers?

The MTR-3B 3 band transceiver is about the size of a pack of playing cards.

SWLing Post readers: I originally published the following post on QRPer.com. I thought I might share it here on the SWLing Post as well since we’ve so many readers who regularly use compact battery packs, earphones, and portable speakers. I’m looking for some advice as I build a super-compact SOTA/POTA field kit around the Mountain Topper MTR-3B. If interested in helping me sort this out, read on:


I received my Mountain Topper MTR-3B last week, and I’ve already taken it on a POTA activation.

POTA Park Hampton Creek Cove

Last weekend, I decided to break it in on a POTA “two-fer” site: Hampton Creek Cove State Natural Area (K-6246) and The Overmountain Victory Trail (K-4577) in Tennessee. Hampton Creek Cove was actually an ATNO (all time new one) so it was a trial by fire!

POTA Park Overmountain Victory Trail

In short, the MTR-3B was marvelous. I’m so impressed.

As I mentioned in a previous post, I’m building a full SOTA/POTA activation kit for the MTR-3B. I already have a kit built around my KX2 and I don’t want to “borrow” any items from it (so I’m not surprised later in the field when an item is missing).

The TalentCell Rechargeable 12V 3000mAh Lithium Ion Battery Pack is the little black box.

For this activation, I powered the MTR-3B with this inexpensive 12V battery pack a friend recommended on Amazon.com (affiliate link). The battery pack is almost identical in size to the MTR-3B and works perfectly. The battery, charger and cable all set me back a whopping $25.

I also used my Whiterook paddle (which needs new paddle arms at this point) but that will soon be replaced with a set of N0SA portable paddles I recently ordered.

Since the MTR-3B has no volume control, I used a pair of 20 year old Sennheiser earphones I bought when I lived in Munich. These have been in a drawer for ages because I now prefer using in-ear earphones with silicon earpieces for better comfort and sound isolation. But the Sennheisers have one thing none of my other earphones sport: in-line volume control.

While the earphones worked well for this activation, I’d still prefer a set of in-ear earphones with in-line volume control. Any suggestions from MTR-3B owners? Also, I’d like a compact amplified speaker with volume control to carry as an option when needed. If you can recommend one, please comment!

I’m writing an article for The Spectrum Monitor magazine about portable power later this year. I noticed that a number of MTR-3B owners swear by 11V rechargeable Lipo cells that are used in the RC and drone markets. Many have a similar compact form-factor as the common 9V battery. I understand, however, some of these cells need special chargers and equipment to balance them.

I would appreciate any and all information about these batteries.

In the meantime, Rich (N8TGQ), recently shared a pic of his Mountain Topper portable pack. Check it out:

MTR Kit

I think it’s brilliant how he’s mounted everything on a compact plastic cutting board inside the case. Rich says that what he loves about this set-up is that everything is there, ready to go–simply plug in the antenna!

Please comment or contact me if you have any suggestions as I build out a compact MTR-3B kit!

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