Sony ICF-SW100: Whip vs. DE31MS active vs. Sony AN-LP1

Click here to view on YouTube.

Guest Post by: Troy Riedel

It’s been a while since I posted a video on my YouTube Channel (but I’ve gotten the urge to make several more videos as I’ve been recently comparing my equipment – 16 portable receivers & many antennas).

I try to tune in to Radio Prague via WRMI on many weekday East Coast USA mornings from 1300-1325 UTC. Yesterday I encountered bad propagation but today was much better.  The video linked to this post is from today – 30JAN2019 recorded around 1310 UTC.

[Sorry, no tripod for this one]

People often ask, “are amplified antennas helpful” – as evidenced by this post from Thomas from a few years ago.

Without repeating the debate, just take a look at this one example.  As stated, reception was pretty good today off the little whip – but – there is an improvement using an amplified antenna.  My question: is there a difference between the two amplified antennas?  And if so, is the difference worth the price?

My TG34 is a clone of the DE31MS – purchased from Tquchina Radio & Component (ebay user: Tao Qu … they used to have an eBay store “Sino Radios” if I recall, but they stopped selling on eBay when the Post started cracking down on shipment of batteries – I actually exchanged an email with a frustrated Tao Qu when they closed the store).

I paid about $21 if I recall for my TG34 (the DE31MS is available today on eBay for as little as $17.28).  I paid over $100 for the Sony AN-LP1 (out of production now and can be listed for as high as $300 on eBay).  So … $21 versus “over $100”.  Is there a difference – and if so – is it 5x the difference – 5x better?!

You be the judge.

P.S. Just a quick slightly over 1-minute video recorded inside my house (sitting in my breakfast nook) … typically “okay” reception but not my usual Listening Post.

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9 thoughts on “Sony ICF-SW100: Whip vs. DE31MS active vs. Sony AN-LP1

  1. Thomas

    Thanks for this comparison, Troy.

    No doubt, amplified loop antennas are improving your breakfast nook reception! I would love to have an AN-LP1 again–I used one for a couple years but it was essentially lent to me from a good buddy. (I was tempted to see if he would forget!) 🙂 Ha ha!

    Amplified loops are typically a solid choice for improving reception while attempting to keep noise at bay. Some are more successful than others, of course. Cheaper amplified vertical or wire antennas are less effective when used indoors only because they tend to amplify the noise as much as they amplify the signal you’re tuned to. Outside, away from sources of RFI, even cheaper amplified wire/vertical antennas can improve reception.

    Thanks again, Troy. Maybe I should scrap the idea of grabbing the AN1-LP and just go for the Degen model!

    Reply
  2. Armozel

    I believe someone did a modded version of the Sony loop antenna and they found the circuit was just using varactors (think solid state variable capacitors) and no actual amplifier IIRC. I’ve been tempted to make Chris Trask’s own varactor tuned loop circuit since the most complex part of his design are the transformers since his experiments shown it actually works pretty well indoors and it can be built to do remote tuning as well.

    Reply
    1. Troy Riedel Post author

      Good point, Armozel. I should have used the term “active” versus the word “amplified” within the body of the post (not just in the title). I am definitely not an electronics guy & I surely try not to portray myself as one. I believe these types of antennas use a “FET” (or similar type of “active” component – hence the term active antenna) versus an “amplifier”.

      Thanks for the feedback!

      Reply
    2. RonF

      FWIW, the transformers in Chris Trask’s designs aren’t hard to wind, and the general design does work as well as any other tuned unamplified loop.

      A tip: follow either his description or his drawings – not both! I personally found it confusing when I tried to reconcile the two and follow both. (But then, thanks to working in telco/rf for years, I’ve had lots of experience at being confused by winding instructions, and maybe his confused me because they /weren’t/ contradictory! ;))

      Personally I’m not a big fan of amplified antennas in general, but it does depend on the situation, local vs distant noise, etc, etc. The thing to remember with antennas in general, and unamplified antennas in particular, is that SNR is almost always more important than signal level. Reducing noise floor & maximising signal works much better than increasing both through amplification.

      Reply
    3. Andrew

      As for active loop antennas, I’ve built this one and can say it works quite well

      http://www.techlib.com/electronics/antennas.html

      there are no coils, the circuit is full solid state and use varactors to tune the loop to the desired frequency, the preamplifier is set to minimal gain and, in effect, is only used to match the loop impedance and to minimize the effect of cable signal loss; the antenna may be either built as an indoor one or as an outdoor one, in this latter case you may use a lenght of CAT5 cable (the one used for networks) to carry the controlbox contact to the active unit connected to the loop

      Another good antenna found at the same site is this one

      http://www.techlib.com/electronics/antennas.html#Improved%20Active%20Antenna

      it’s basically a “miniwhip” although it’s different from the usual one, the above uses a simple antenna buffer which offers no amplification but just acts as an impedance matcher, the unit may be used with either a short length of wire (5 to 6 ft at max) or a short telescopic whip and in either case, offers good performance and, given the very small size, may be successfully used as a field-day antenna; in such a case the buffer unit may be powered using (e.g.) a pair of 9V batteries

      Reply
      1. Andrew

        Forgot, that tuned loop, that is the one shown here

        http://www.techlib.com/electronics/antennas.html

        is a quite interesting antenna to operate with an SDR, you connect the loop, fire the SDR and then start turning the tuning pot, and you immediately see the noise/signal peak move along the waterfall while you turn the tuning knob 🙂 my suggestion is to either use a 10 turns pot for the tuning or (better) a vernier dial; with the latter you’ll be able to make a note about the knob position for the main bands so that you’ll be then able to quickly tune the loop for a given band

        Reply
  3. Troy Riedel Post author

    Thanks for the reply Frank – good tip – and yes, I agree! You won’t solve ALL reception problems, but for the price of dinner – $18 for the DE31MS – it’s money well spent.

    I’ve been experimenting with the Sony AN-101/102 antenna module. For other readers unaware, the AN-101 comes with a controller and was made exclusively for the Sony ICF-SW1. That controller works with the SW1 but not with any other portables that I own (it has to do with the 3.5mm plug – and power – but I digress). I’ve used the AN-101/102 standalone and have also substituted the TG34 (DE31MS) as the in-line controller … it doesn’t even have to be turned on – it’s only a conduit of sorts – and both of those combinations work as well (the latter the best – you’re simply using the Sony AN-101/102 Whip module in place of the DE31MS antenna).

    That’s the fun part, huh Frank? Playing and experimenting to see what works best with – and within – our situations. Thanks again for the comment & tip, mate!

    Reply
    1. Frank

      You´re very welcome, Troy. Glad to read it is not that unusual to combine two small active loops into one, to combine each other´s selectivity. I was surprised myself when a few years ago I simply hung them over each other and suddenly got Peru and a few non-standard Brazilians. This is still my standard setup here, mostly to listen to the German small power stations and their relayed programs in the 49 meter band, such as Uncle Bill´s Melting Pot. Works fine here with both loops over each other , but I find I need to have the power on both. It´s probably the next best thing to a self-made hoola hoop loop.

      In 2017 I spent the Easter holidays in Indonesia and I had the Sony ICF-SW-100 and the DE31MS antenna along, Wanted to hunt PNG…alas, only station I received in the 3 MHz area from home in the middle of a big Javanese city was RRI Palangkaraya, the one on 3325 khz. Additionally, I listened a lot to local AM stations and amateur radio, the latter was helped a lot by the loop antenna when I compared it with a simple 2 meter long wire. Had my laptop for work along and the Sony-Degen antenna combo served me well over 3 1/2 weeks every afternoon before neighbors turned on their LED lamps…

      Reply
  4. Frank

    I like to use both at the same time, hanging on top of each other and using the Degen one for fine-tuning. Before I had to replace the DSL modem towards a new one, a FritzBox, I was able to get Radio Tarma even in my bedroom using this setup. Both are great antennas for indoor use.

    Reply

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