Tag Archives: Anil Raj

Anil’s hack: Using a smart phone battery bank to power portable receivers

Many thanks to SWLing Post contributor, Anil Raj, who writes:

I wanted to share a small but useful hack with your readers.

I use a common garden variety smartphone “Powerbank” 10,000 mAH Li Ion pack to power my Sony 7600GR which is perfectly happy with the 5V which the pack supplies. [See photo above.] I see no reason why this won’t work with other radios which require a 6V supply.

As you can imagine, the setup typically lasts for many weeks of extended daily listening and recharges in a jiffy. However, one needs to sacrifice a USB cable by soldering a DC plug at the other end. Haven’t bought AA batteries in a long time…

Thank you, Anil! What a simple but useful hack. The best part is, battery packs/banks are  very inexpensive these days and, I for one, have a number of USB cables I could sacrifice for the job!

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A review of CozyPhones sleep headphones

A few months ago, SWLing Post contributor, Mario Filippi–being both a good friend and an (ahem!) enabler–sent the following note:

My XYL bought me a set of CozyPhones for Christmas.  If you like listening to the radio, especially at night while in bed, these work great. Speakers are nice and flat.  And if you are outdoors you can listen to shortwave and not suffer from ear frostbite hihi.


[I’ve attached the photo below of] the one I got.  Absolutely amazing!

Little did Mario know that, back in 2014, I ordered a pair of similar sleep headphones by the company Acoustic Sheep after reading SWLing Post contributor Anil Raj’s brilliant entry in our Virtual Radio Challenge II.

I purchased an open-box pair of the Acoustic Sheep SleepPhones for about $33 and was very pleased with the purchased…initially, at least.

I used the Acoustic Sheep SleepPhones a couple nights a week for several months. I was disappointed, however, when the braided jacketing started coming off of the headphone cord, bunching up, and the rubberized jacketing underneath began staining my pillowcase, so I was no longer able to wear them at home or when traveling. My wife was amused and said it looked as if I had worn mascara to bed.  Well, at least until she attempted to clean the marks off of the pillowcase with limited success.

I feel it’s only fair to state that my SleepPhones were a fairly new product in 2014, thus may have been an early iteration and may not accurately reflect what the product is like currently. I’m guessing that Acoustic Sheep have improved the design and reinforced the jacketing since then, because they seem to enjoy relatively positive reviews on Amazon.

Panasonic Ergo Fit (in-ear) Headphones

At any rate, I set the troublesome SleepPhones aside and and went back to using my go-to in-ear sleep phones: the Panasonic Ergo Fit Headphones. The Panasonics are the least uncomfortable of all of the in-ear headphones and do a decent job of isolating any environmental noises while you sleep. Still, having something inside your ear while you slumber isn’t exactly the definition of comfort.

Enter CozyPhones

I replied to Mario’s email telling him about my experience with the SleepPhones. He encouraged me to give the CozyPhones a try.

I took a quick glance at Amazon (the only distributor I could find for CozyPhones) and the price for a pair was only $22. Almost $16 cheaper than a pair of new SleepPhones?  I even noticed combo packs with two sets of CozyPhones for $24. My doubts about quality resurfaced.

I decided to contact CozyPhones customer service directly and ask if their headphones were likely to experience the same problem as my SleepPhones–I mentioned my hesitancy and the fact these would likely be mentioned in a frank review (hint, hint: if quality is poor, this will get a negative review).

They promptly addressed my concerns, standing confidently behind their product, and even offered to send a sample. One week later, the CozyPhones arrived.

The CozyPhones arrived in a thick plastic re-sealable bag (seen above)–a nice touch! Included in the package were both the headphones and a satin carry bag.


Let’s be frank here: with sleep phones, I’m not expecting the same audio fidelity I would achieve with my Sennheiser HD558s––which, by the way, would be incredibly uncomfortable as sleep headphone; I simply wanted to be able to listen to my bedside radio as I drifted off.

Here’s what I do expect from a pair of sleep headphones:

  • decent audio fidelity at low volume levels–something suitable for listening to AM or shortwave radio
  • something with enough sound isolation that it won’t keep my wife awake while I listen to the Voice of Greece into the wee hours
  • comfort around my head and against my ears as I lie on a pillow…actually, this might be the #1 priority for me
  • headband’s earphones (speakers) stay in place, don’t shift within the band
  • quality construction and the potential for product longevity
  • no black marks on my pillowcase!

Let’s see how the CozyPhones deliver on my points:

Audio fidelity

The CozyPhones easily pass this test. I’m very pleased with audio fidelity for radio listening. Indeed, the audio response is pretty well tailored for AM/SW broadcast listening. FM and music sounds fine, too; good enough that I would consider wearing these in the winter while hiking. Again, these are not audiophile quality to be sure, but they surpass my needs for this application.

Sound isolation

The CozyPhones do a respectable job in this regard. My wife can’t hear what I’m listening to while lying in bed, not even a hint of what I hear. Now, if I were hard of hearing, listening to music and had the volume cranked up, I’m sure she’d at least hear percussive sounds.


I should note hear that there are essentially four versions of CozyPhones:

CozyPhones sent me the second version mentioned above, the headphones with Cool Mesh lining and a lightweight Lycra-like exterior. I was quite pleased, as it’s what I would have selected. If anything, I tend to generate a lot of heat, so don’t like products that make me feel even warmer at night while I sleep.

After a few months with the CozyPhones I can say that I’m very pleased with how comfortable they are. The material is soft, the headphone speakers are very thin and seem to stay in place even as I move around and adjust my head on the pillow during the night.


The SleepPhones I purchased in 2014, in contrast, were also comfortable, but the earphones, essentially mini speakers, tended to migrate within the soft headband. I’d often wake up and find the speakers had completely moved within the band away from my ears; it was then a matter of trying to bunch up the headband material and re-position the speakers.

The CozyPhones don’t seem to have this problem. The ear speakers might shift a little some nights, but not enough to be annoying–certainly not as the SleepPhones initially did.

The braided headphones cord is non-obtrusive and comes out the back of the headphones. So far, the CozyPhones haven’t suffered the same fate as the SleepPhones–the braid has remained intact and seems quite sturdy, resilient to light tugging and normal movement.

And as for my pillowcase?  Still clean…no black marks.


If, like me, you enjoy listening to radio in bed, but don’t want to disturb your partner, CozyPhones really are a fantastic option.

Perhaps as a side effect of my years of SW listening, I find I’m a bit sensitive to environmental noises when I travel; often hallway noises, nearby traffic, children screaming, doors slamming, can disturb me, so I never leave home without earphones in my pack to quiet the noise. Quite often I’ll listen to my radio at bedtime, then, right before nodding off, I tune to a blank spot on the AM dial to the soothing sound of static. This “white noise” tends to drown out other abrupt environmental noises, and I find I drift off peacefully.

I think CozyPhones will serve you well. At $18-22 shipped? I think they’re a good bargain and a great gift. In fact, I intend to buy a pair for my wife!  Shhhh…don’t tell her.

Click here to view CozyPhones on Amazon.

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eBay find: the “mythical” Sony CRF-V21

Image source: Universal Radio

Image source: Universal Radio

Many thanks to SWLing Post contributor, Anil, who writes:

Here is a link to an Ebay auction for the mythical Sony CRF-V21. In all my years, I have never seen one for sale before and it might be interesting for some blog readers…

Click here to view on eBay.

Mythical is, indeed, the correct word for the Sony CRF-V21, Anil!

Check out our previous post that mentions the Sony CRF-V21.

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Guest Post: Anil reviews the FiFi-SDR receiver kit 2.0

Many thanks to SWLing Post reader, Anil Raj, for sharing his review of the FiFi-SDR receiver kit 2.0:


The perfect radio for business travellers?

I travel regularly, or should I say commute between Europe and Asia, and have been on the lookout for a small receiver with good performance that would be easy to carry with me. I never travel without my laptop so an SDR would be the sensible thing to look for. A few weeks back the tiny FiFi SDR receiver caught my interest as I was browsing the website of Funkamateur http://www.box73.com/ the excellent German ham radio magazine. It looked promising as it had an impressive bank of filters covering all the way from LF to HF. Also, the front end is designed to emphasize sensitivity, so that it can work well with short wire antennas. It also had a built in sound card which would make interfacing to my computer a simple job.



The price was certainly right – $ 169. I ordered it, and it showed up in my mailbox a few days later. It is offered as a “kit” though in practice all that needs to be done is to solder a couple of connectors and sockets. All the surface SMD components are pre-soldered, and the rugged extruded case has die cut holes for the connectors and controls making the mechanical assembly very simple. The entire exercise took me about 20 minutes until the receiver was plugged in and powered up.


Since I use a Mac the choice of SDR software is a lot more restricted than that for Windows. I did however find free software called SDR Radio (http://dl2sdr.homepage.t-online.de/) developed by DL2SDR which does a great job of partnering with the FiFi and my Mac.

SDR Radio is still in development, so the UI can a bit rough at the edges at times. Also, configuring the Audio and MIDI settings on my Mac took a bit of work, but DL2SDR Sebastian was quick to reply to my mails requesting help when I got stuck.

So how does it all sound? While I am sure that there may be better performing SDR radios out there, what this little matchbox sized receiver does is simply amazing. Users running Windows will have access to much more sophisticated applications than the simple programs available for Mac and will be better able to compare this radio. However, it does an outstanding job of handling both AM broadcast as well as CW and SSB utility and Ham signals. While SDR Radio does not offer a lot of bells and whistles at present, the continuously variable bandwidth which can be dialled in to almost zero, and effective notch filter get the job done very well. In empirical testing and comparisons with the Palstar R30C, the FiFi easily outclassed the older analog radio (and the Palstar is no slouch, especially on the lower frequencies).


In summary, this is going to be the radio that I will be taking with me on all my travels from now on. It is tiny, ruggedly built, and has excellent RF performance, especially at lower frequencies.

Many thanks for your review, Anil!

The FiFi SDR does indeed sound like an ideal SDR for travel. Like you, I am usually limited by the SDR applications available on the Mac OS. While I use a Windows 7 PC at home, on the road, I travel with the MacBook Air (a superb laptop!).

Click here to view details and purchase a FiFi SDR ($169 shipping included).

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