Category Archives: Radio Modifications

You’ve Been Warned: Emilio just brought a Grundig Frankenradio to life–!

Many thanks to SWLing Post contributor (and certified mad scientist), Emilio Ruiz, who writes:

Recently I was given a broken Grundig G8 Traveler II. This radio had an accident–the case, speaker, tuning knob, and volume controls were all broken or damaged.

I discovered that the tuning and volume controls are not potentiometers, they are a rotary encoders, so I substituted the tiny and broken original controls with rotary encoders (typically used for Arduino projects), but I needed to remove the 10 kiloohms resistor to work properly (only used the CLK, DT, and GND pins).

All materials were reused from other things, the result is like a “Frankenstein radio”.

The “telescopic” antenna is a tape measure/flexometer which was broken too. I replaced the original speaker (which I think was another impedance) with a proper 8 ohms speaker which produced low volume, so i decide add a Pam8403 amplifier module for best performance. The total current drain is 0.10 amp for a regular “loud” audio level.

So the Grundig Frankie is alive!!… It’s alive!!

Click here to view video in new window.

This is brilliant, Emilio! Although this radio is quite scary–and, let’s face it, “post-apocalyptic”–I think it’s absolutely amazing! I love the handle and the tape measure antenna. You, sir, are a mad scientist and I look forward to your next creation! (I’ll just take shelter first!) 🙂

Anyone else ever created a Frankenradio? Please comment!

Video: Antonio’s Kenwood R-2000 Modifications

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Many thanks to SWLing Post contributor, Dan Robinson, who shares the following:

Antonio Fernandez, who is in Spain, posted this on the Extreme page. Very interesting R-2000 mods:

Major modifications are adjustable RF GAIN (using the former TONE control), BFO Pitch control (former AM Squelch, FM Squelch is retained) and DSP Audio filtering for SSB and CW. Internal DSP module is SOTABEAMS Laserbeam Filter Module. The former DIMMER and NB push switches are used for switching on (bypassing) the DSP module and bandwidth (CW, SSB) selection.

Click here to view on YouTube.

Those are brilliant modifications on a classic receiver! Thank you for sharing, Dan!

Check out more videos from Antonio Fernandez on his YouTube channel.

Jesse’s DX-390/ATS-818 modifications

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Many thanks to SWLing Post contributor, Jesse (W9JES) who writes:

I’ve been busy enhancing my Radio Shack DX-390. I added an IF-Out jack for my SDR, changed out the light for a LED, added a latch circuit for the light switch, added static protection, and disabled auto-mute. My blog with full instructions is at www.w9jes.com

Thank you, Jesse! Here are links to the various modifications Jesse has documented:

Click here to check out Jesse’s website.

Imre’s HanRongDa HRD-737 modification increases sensitivity

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Many thanks to SWLing Post contributor, Imre Olajos, who writes:

Hi, HRD 737 lovers! I have a good news!

I (became brave enough to) modify my HRD-737.

I tried reverse-engineering- but I gave up. No numbers on IC-s. I found specifications for the analog switches (one for each band ) and found information about the transistors around those analog switch IC-s. Nice, 1 GHz fT transistors, all surface mount, so I gave up that line.

I found an NPN SM transistor in a damaged TV remote. It is only a 300 MHz transistor but
I had no better than that, so I started to build a little antenna amplifier circuit, wide band and simple.

I lost a few SM capacitors during the soldering but I have plenty of those. So the 1/4 square inch circuit board was finished last week. I tested it with an external 3 volt battery and I found it good working. Today ( 07-27-2019 ) I opened up the HRD-737 and wired it into the radio.
The results are much better than I expected. The HDR-737 became a good shortwave radio!

When I touch the built in antenna by my finger, radio is sensing the touch and station comes in. This effect was not there before. Radio became more sensitive on CB band than my Realistic DX392.

I have a YouTube channel [in the following video/slideshow] and I will show you the little ugly but great working circuit in the radio:

Click here to view on YouTube.

Later on next week I will try to record some video of the shortwave reception and post up it on the same YouTube channel.

I am a shortwave lover since 50+ years and I will be very happy to share the good news with others. Now I can listen my Greek music on this little radio, on 9420 kHz. Yes, the radio became [more sensitive than I had hoped].

You can see my other shortwave radios on my YouTube channel too, Have fun and never give up the hope!

Many thanks, Imre, for sharing and documenting this modification. One of the lessons here, too, is that if you have an inexpensive radio like the HanRongDa HRD-737 and you feel tempted to try a modification, there’s little to lose. It’s not like modifying a $1000 transceiver–just dig into the little radio and give it a go. If you harm the radio, you’ve only invested $37 or so in the project. That’s a much better solution than letting it sit on a shelf collecting dust because it’s not sensitive enough! Well played, Imre!

Video: N1SPY brings a GE seven band radio back to life!

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Many thanks to SWLing Post contributor, Ivan Cholakov, who writes:

Thomas Cholakov (N1SPY) picked up an old General Electric radio from the 2019 Orlando Hamcation and brought it back to life. Unfortunately with all of the radio’s 7 bands, it did not have shortwave.

Click here to watch on YouTube.

Brilliant job resurrecting that GE portable, Tommy!!! Thank you for sharing.

Tivdio V-115: Simple modification to abate internally-generated noise

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Many thanks to SWLing Post contributor, Marc Thomas, who shares a link to this site which describes modifications to eliminate the Tivdio V-115’s internal noise.

In a nutshell, the author made two small mods:

Decouple the power/battery with an electrolytic capacitor of around 10uF soldered to the battery connector inside the radio (see photo above)
The author also grounded the speaker, but didn’t test to see if this alone had any positive impact

I could not find contact details for the author of this mod, so I hope they don’t mind the fact I shared it here on the SWLing Post.

Note that the Tivdio V-115 is also known as the Audiomax SRW-710S and Kaimeda SRW-710S (and likely rebadged as a number of other models).

Click here to read reviews of this radio.

Retailers:

An external battery pack for the Sony ICF-SW35?

1 Reply

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

Hi Thomas I enjoy reading your blog and often when I put a question in Google yours is the first on the list so I wonder if you’d mind if I ask you a question about the Sony SW35.

I’m interested to try powering it from a power bank but I have no idea what DC plug to buy for it as I bought it second-hand without an adaptor.

I thought about taking a couple of wires out of the battery compartment but it wouldn’t look as nice so any help you could give me would be much appreciated.

Great question, Adam!

You can certainly find a DC plug that will work with the ICF-SW35. I believe this same plug was used with a number of Sony Walkman type players back in the day. You might be able to find one at the local charity/thrift shop in their power cord jumble.

I do know that the coaxial type plug needs to have positive tip polarity (click here to read about this in the owner’s manual) and the radio requires 4.5 VDC . The OEM power adapter (Model AC-E45HG) provided 700 mAh, but I don’t know what the ‘SW35 actually requires (other than something equal to or less than 700 mAh).

One option would be to find a 12VDC to 4.5 VDC converter like the Sony DCC-E345 and plug it into a 12VDC source (there are a number of high capacity 12V battery packs on the market).

Of course, you could also build your own external source by purchasing an appropriately sized external battery holder. I would use a D cell holder (I assume one to hold 3 cells at 1.5VDC x 3 = 4.5 VDC) which would provide much better capacity than a AA cell holder. (Something like this.)

I haven’t been able to determine the +/- voltage tolerance of the ICF-SW35, so I would keep the supply voltage figure at or below 4.5 volts.

One crucial number I’m missing is the coaxial plug size. I can’t seem to find a spec for OEM Sony AC-E45HG. I hope a reader might be able to help us here.

Post readers: Can anyone confirm the DC plug size for the Sony ICF-SW35? If you have any other advice or tips for Adam, please comment!