Category Archives: How To

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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Doctor Vlado repairs the Panasonic RF-2200 (Part 1)

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Last year, at Hamvention, I picked up a Panasonic RF-2200 for $70. It came with the original box, manual and was in superb cosmetic condition.

The seller told me that over the years he exclusively used the radio to listen to a local FM station.

At that price, I didn’t hesitate to make the purchase even if this would have simply been a non-functioning parts radio for my other RF-2200.

After I brought the radio home, I unpacked it and gave it a quick test.

FM worked brilliantly. Mediumwave and shortwave, however, were essentially deaf. I made the assumption that the ‘2200’s switches and pots likely needed cleaning with DeoxIT. The next day, I was leaving for a two month trip to Canada though, so I packed the RF-2200 back into its box and set it to the side of my shack table.

Fast-forward to yesterday…

While digging around my shack, I re-discovered the boxed RF-2200. Since I was planning to visit my buddy Vlado (the best radio repair guy in the world) yesterday evening, I thought I’d take the RF-2200 and do a proper contact cleaning. Several of the RF-2200’s switches and pots cannot be easily cleaned without removing the chassis.

(Click photos to enlarge.)

Vlado is familiar with the RF-2200 and since it’s not the easiest radio to work on, I asked for his expert hands on the job. Within seconds of handing him the radio, he plugged it in, tested the switches and pots, then removed the back cover (disconnecting the battery compartment leads) and then the front cover (disconnecting the speaker leads).

The magic behind the RF-2200’s classic analog dial:
Vlado offered a word of caution to anyone operating on their RF-2200: as you can see in the photo below, the dial string snakes around the front of the radio and is very close to some key components. You must exercise caution when having a soldering iron tip near the string, or using lubricants nearby.I didn’t realize this, but by the time Vlado started taking apart the RF-2200, he had already determined that even though the contacts needed cleaning, this wasn’t the source of the audio problem for the MW and SW bands.Vlado expertly pulled out the pot for the FM/AM/SW selection–not an easy task–began cleaning it, testing it and re-soldering contacts.

Vlado determined the pot was actually in good shape, thus started testing the rest of the circuit.

After a few minutes of performing tests and getting intermittent performance, he determined that at least one, if not more, of the RF-2200’s caps need to be replaced. Of course, neither one of us was terribly surprised. At this point though, it was getting late and I had an early wake up time in the morning, so I left my RF-2200 with Vlado.

Am I worried about this prognosis? No, not in the slightest…

Doctor Vlado is on the job!

Vlado will have the RF-2200 back on the air in no time, working as well as it did when it was new. He’s actually performed a similar RF-2200 repair for an SWLing Post reader and I’m willing to bet this repair job is relatively simple compared to most he encounters (including the Icom IC-7200 he recently repaired after it was hit by lightening!).

I’ll try to post a “Part 2” update with photos of the RF-2200 repair. Follow the tag: Panasonic RF-2200 Repair

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Make your own 3-D printed crystal radio

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(Source: Southgate ARC)

Did you know you can build your very own working 3D-printed radio – without any soldering, electronics experience, electric cord, or even batteries?

Digital Trends reports that’s exactly what talented Houston, Texas-based 3D-printing and electronics enthusiast Sage Hansen has created. And he’s willing to show you how to do it, too.

Called a crystal radio receiver, or sometimes a “cat’s whisker receiver,” this is an incredibly simple type of radio receiver that was popular in the earliest days of radio. The only power it requires to work is the received radio signal, which is used to produce sound. It is named after its most important component, the crystal detector or diode.

“AM radio was one of the first ways of transmitting audio to a very broad audience in the early 1900s, but it is still very popular today,” Hansen told Digital Trends. “It starts with the radio station converting their audio sound waves into electromagnetic waves, which can travel great distances.

Each radio station uses a specific frequency that is constant, but the sound waves are mixed so they amplify and modulate the base radio wave. What makes the crystal radio so exciting is how simple the circuit is, and how it can be made out of normal household items.

Watch the video and read the full story at
https://www.digitaltrends.com/cool-tech/3d-printed-working-radio/

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Tecsun PL-880 hidden feature/hack: 1 kHz bandwidth on shortwave

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[Note: This procedure was updated and simplified by Guillermo on 22 December 2017]

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

I own the PL-880 and just discovered a new feature : a 1.0 kHz bandwidth mode on shortwave (SW only not in MW).

The procedure to get it is as follows:

Turn on the radio and tune any frecuency on SW . There is no need to connect or disconnect an external antenna and turn on or off the radio during this procedure.

Be sure that on SW the 4 button feature(press 4 for about 2 seconds) is ON and 9 button feature(press 9 for about 2 seconds) indicates a value of 13 or more and not less than 10.

Then turn OFF 4 button feature and then ON again . Press BW button and see the 1.0khz new BW on the screen. Now you can use it permanently on SW and ALSO on MW , UNTIL you press BW button again .

Well, I hope you understand this description–if not please let me know, and tell me if it works on your unit, or it is just works on mine.

Thank you, Guillermo! I see where this is somewhat of a fragile adjustment in that a number of actions could change the bandwidth back to a previous setting, but nonetheless is quite a fascinating hack/hidden feature! Thank you and I’ll add this to our list of PL-880 hidden features.

Post readers: please comment if you can successfully enable the 1.0 kHz bandwidth on your unit. Please comment with your radio’s manufacture or purchase date if possible.

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Tecsun PL-660: A simple hack to scan the air band

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Many thanks to SWLing Post contributor, Bruce F, who writes:

HI Thomas, I thought I would put this idea out to your site – in case it isn’t already there. It’s a brilliant solution to the apparent lack of a working Air Band scan function on the Tecsun PL-660. Note – I did not come up with this idea, but came across it in a Yahoo group.

It IS possible to scan the Air Band on the PL660, as long as you have picked out WHICH Air Band frequencies are in use in your area. There are websites which list these frequencies for each airport:

AirNav.com

RadioReference.com

Here’s how to set up the PL-660:

Pick an empty page in the Memory.

Put in a shortwave frequency in the first empty space; the “00” slot.

Then fill in the succeeding spaces on that page with the Air Band frequencies you’ve chosen.

Now go back to the “00” slot and hold down the scan button.

Works on my set!

What a cool trick! I’ve lent my PL-660 to a friend, but as soon as I get it back, I’ll also try this trick by setting up a page dedicated to my local aviation frequencies!

Thanks, Bruce!

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Video: Comparing the SDRplay RSP1 with the RSP1A and intro to SDRuno

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(Source: Jon Hudson on the SDRplay Facebook page)

This latest video from Mike starts by showing the differences between the RSP1 and the RSP1A, and then gives an excellent demonstration of how the latest SDRuno works – this is a great place to start for any newcomers to SDRuno – https://youtu.be/qUZerxeHJvc

We continue to regularly add video guides to our Youtube Channel. The original series are listed in a playlist called ‘Part 1’ – newer guides are listed in a playlist called ‘Part 2’

The SDRplay YouTube Channel can be found here: https://www.youtube.com/c/SDRplayRSP

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Rolf’s PL-680 modification allows external antenna on LW and MW

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The Tecsun PL-680

Many thanks to SWLing Post contributor, Rolf Snijder, who writes:

I did a modification today on the Tecsun PL-680 [which allows for an] external antenna on LW and MW.

The internal ferriet is also working, but on my active loop, MW and LW is now working !

So far away stations I can now receive on this portable radio.
It is only a560 pF capacitor added!

Click to enlarge.

Click to enlarge.

It works on LW and MW now with this mod.

FM is less now I think, maybe I will put it on a switch so I can turn it off.
And now also the ferrite is still working, so I hope to find a solution for that.

Many thanks for sharing your modification and photos, Rolf! Check out Rolf’s other PL-680 mod by clicking here.

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