Many thanks to Joris van Scheindelen (PE1KTH)–an SWLing Post contributor from the Netherlands–for the following guest post:

High Tech AM-FM DSP Receiver From

The old mode AM is still an interesting mode for amateur radio communication, also in amplitude CW.

Building your receiver is not difficult and quite fun. The semiconductor industry makes interesting integrated receiver chips today that will be useful for an AM receiver. Not only for broadcast reception but also for amateur AM reception or as part of an AM transceiver.

Silicon Labs also makes Si4734/35 receivers; these need a CPU to control the receiver, but are of interest for amateur use because the frequency can be tuned in 1 KHz steps and the audio channel bandwidth in 7 steps. There is no need for the transmitter to be on the receiving channel…

Si4835 AM-FM receiver

Looking for a small SW broadcast receiver design, and pocket size, I came to the excellent range of modern DSP receivers in a single chip from Slicon Labs.

I made a test bed set up has been made for the Si4835 AM-FM receiver.

The target specification was:

• minimal components,
• no micro-controller,
• low power,
• backlash free mechanical tuning,
• good sensitivity,
• earphone,
• robust housing,
• a short and small antenna system for outdoor use,
• and minimal controls.

The Si4835 makes miniature design possible on a PCB (see photo Figure 1).

The red Dip (band) switch was replaced by a rotary switch in the final receiver design (Figure 4).

The receiver power is minimal 2 x 1.2 = 2.4 volts or a one cell LI-ION accu.
5 volts is the maximum for the Si4835 chip; current consumption is 30 mA.

Fig 1. Testbed setup for the Si4835.

The receiver has an RF pre-amplifier transistor and the LF amplifier is the TDA7050T.
All receiver functions are in the chip; the schematic is very simple and can be built with minimal components (see schematic appnote AN555 Fig 2. below).

Only an LF amplifier has to be added to complete the receiver.

Fig 2. Receiver schematic Si4835 in the AN555 application note.

The Si4835 receiver has the following frequency bands–they are divided in sub bands 800 or 900 KHz wide (See Figure 3). The frequency step tuning is 10 kHz on AM, following the international broadcast raster standard.

Fig 3. Si4835 receiver sub bands.

This means there are 80 or 90 receive channels in the sub bands and make finding the BC stations on the scale more easy. The 10 KHz scale steps are linear. The frequency stability is locked to the 32 kHz X-tal via the synthesizer so there is no frequency drift. The AM LF audio channel is 5 kHz wide set by the DSP filter. Volume control can be done width 2 up-down push switches or by a LF potentiometer..

Fig 4. The experimental pocket aluminium receiver housing on PCB2.

Receiving results

I have been testing many hours and I am surprised about this little receiver.

The receiving results are excellent on FM and AM and signals of 2 -3 uV are well received.

Also the audio quality is good–especially on FM. As can be seen in the frequency table the 40 and 20 meter band are in the range. Clear AM phone amateur transmission has been received when the transmitter was tuned on the 10 kHz raster in 40 meter band on AM.

Also AM modulated CW signals can be received bud not un-modulated carrier CW–they sound “plop…plop”.

The 5 kHz wide LF channel is a bid too wide so many CW signals pass through the audio at the time, but if AM modulated that should not be a serious problem.

The broadcast stations in the SW bands (when the daytime conditions are good) up to 20 MHz are good and strong.

Conclusions

The Si4835 receiver can be a fine broadcast receiver for outdoor work and if an AM transmitter is tuned in the 10 kHz raster this receiver can also used for amateur phone reception.

Addendum: The Si4734/35 is a better amateur AM Receiver

The Si4734 and Si4735 are a better receiver choice for amateur AM purpose because the frequency tuning can be done in 1 kHz steps. Also the BW of the LF channel can be adjusted to 1 kHz wide.

In Fig 5. from the programming APP note you see the code 0X3102 AM CHANNEL_FILTER it is possible to adjust the audio width by sending this code to the Si4734/35.

Fig 5. From the programming APP note

The LF bandwidth can be set on 1, 1.8, 2.5, 2, 3, 4 and 6 kHz wide.

This is excellent for modulated CW and AM phone discrimination in the audio channel.

The disadvantage is the need of an CPU and LCD display, “away from a minimalistic design”.

See also the note 1 and 2 improved 100 Hz rejection. See data sheet of the Si4734/35.

It look like that this receiver is a good receiver for building a modern AM-(AM)CW receiver or in a transceiver application. Tuning can be done digitally.

Think about this receiver [and the Si4835 chipset] when you intent to build a high tech AM – T/RX.

73 ‘ Joris van Scheindelen PE1KTH

What a fantastic home-brew receiver, Joris! I love the simple design of your receiver and the fact that it’s quite portable.  Thanks so much for sharing your notes and documentation.

SWLing Post contributor, Robert Gulley, writes:

I recently purchased an Oxo Good Grips Turntable, 16” from Amazon. As the photos show, the size of the turntable can hold a fairly large radio (CC Radio EP and Select-a-tenna) on the turntable in almost any configuration. (Of course the CC Radio EP doesn’t need the Select-a-tenna, just used for illustration purposes for size.)

At $16.99 I think it is a good bargain, and seems quite capable of turning smoothly even with this amount of weight.

Click here to view on Amazon.com.

Many thanks, Robert! I think that turntable is large enough to hold pretty much any portable radio; thanks so much for the photos (especially the one your kitty cat photo bombed, above!). I have several OXO products in my kitchen and have never been disappointed with quality, so I expect this turntable will last you a very long time.

Readers: If you haven’t checked out Robert’s radio blog, All Things Radio, I encourage you to do so!

My pal, Jeff McMahon, over at the Herculodge writes:

A week ago, my Sangean WR-2 was fried when the electric company surged my house. I replaced it with the Grundig S350DL but it drifted too much.

I then used my superior Crane-SW radio (same size as the big Grundig) and guess what? It died! Those cheap radios today seem to die after 5 years or so.

So I looked through the myriad of unused radios in my cabinet and unearthed a Sangean CL-100 purchased in 2011. For whatever reason, it no longer works with batteries (old double As were left in there and leaked a tiny bit but compartment looked clean enough), so I plugged it in and it works.

FM is better than my Sangean WR-2. I think it has a DSP chip.
AM is better with low background noise, amazing for a radio this small.

Speaker is not as good as the WR-2, but it’s clear and okay since I listen mostly through earbuds.

Tiny footprint on my bedside table, which I like.

The menu system is easy enough to use though I wonder if down the road I’ll encounter bugs.

I bought this for about $45 and now it’s about $12 more.

It really suits my needs.

[A] man needs a strong performing bedside radio. That’s the backbone of a collection.

Indeed it is, Jeff!

I see why you like the CL-100. For a bedside radio, the flat/horizontal form factor also makes it less susceptible to being knocked over when you reach for it in the dark.

As for battery operation, you may try removing some of the corrosion on the battery contacts with a file or something mildly abrasive. I’d also hit it with a little Deoxit. (Though knowing Jeff, he’s probably already on this.)

Having your Sangean WR-2 fried by the power company is bad enough, but then finding out your C.Crane CCradio-SW isn’t working just adds insult to injury.

I should note that, in general, I think C.Crane products are built as well as most others on the market.

I often wonder if premature product failures have less to do with poor quality control and more to do with the lead-free solder electronics manufacturers are forced to use these days.

Many moons ago, a friend sent me this article which outlines concerns about the use of lead-free solder in the military and aerospace industries. It’s worth a read and certainly points out inherent flaws. I often wonder if nearly all of our modern consumer electronics are prone to fail within a decade; you know, planned obsolescence at its worst. Perhaps I’m overreacting.

When I build kits or repair electronics, I only use traditional lead-based solder. Not only is it easier to use, but I feel it will last longer.

SWLing Post reader, Marty (W5MRM), comments:

I recently picked up a Sangean ATS-909X to use as a bedside radio.

This blog post inspired me to put together a video review of the ATS-909X as a bedside radio. The video review can be found on my youtube page [or via the embedded player below]:

Great video, Marty, and thanks for the thorough review!

You can follow all of Marty’s videos on YouTube by visiting this page.

My pal, Jeff McMahon, over at the Herculodge, has just posted a video review of the Sangean PR-D4 portable radio. In summary, he writes:

“It’s a great radio with top FM, AM, and speaker sound. It blows away my C.Crane Radio-2E. Lack of illumination, however, makes it less than ideal as a bedside clock radio.”

Wow! I’m most impressed that Jeff places the PR-D4W (which retails for $69 on Amazon) above the venerable CCRadio-2E (which retails for $169 on Amazon) in terms of AM performance.

I just checked and it appears that Universal Radio also retails the PR-D4W for $69.95.

Follow Jeff at the Herculodge and on YouTube.

Many thanks to SWLing Post reader, Paul Walker, who writes:

Thomas.. I know this isn’t quite SW news anymore, but Radio Kiribati usedto be on SW a while ago and is now on AM.

I just found out something to those of us interested in Pacific radio signals. Radio Kiribati 1440 JUST started a live web stream…JUST…as in, like within the last few days!

The audio levels can be a bit loud and overdriven at times, but i am corresponding with their Chief Engineer and the Radio station manager at the Broadcasting & Publications Authority in an effort to get levels set just right.

The audio is average and I wouldn’t expect much more, quality wise, then what they’ve got now.. as most of these stations have hare basics when it comes to some equipment.
The Radio Kiribati stream was just added to the Reciva.com database for internet radios and should be there soon if it isn’t already.

The stream is at http://202.6.120.13:8000/ The stream itself is of amazing quality at 64k vorbis, which sounds good to my ears via my CC Wifi Radio and CCrane Senta speaker.

Radio Kiribati only broadcasts local programming at certain times of day. Sometimes I’ll hear Radio New Zealand International outside of local broadcasting, other times I won’t.

TX times are as follows…most of their programming is in their native language, which is Gilbertese according to Wikipedia. It’s a Micronesian language of the Austronesian language family. They do three segments of English broadcasting every day, some 30 minutes long and one is an hour long.
Kiribati is UTC+14… at 416pm Thursday in Southwest Arkansas, where i am.. it’s 916am Friday morning in Kiribati.

• Morning: 0700am to 0830am. English at 8am
• Lunch: 1200 noon to 1330. English at 1300
• Evening: 1700 to 2130. English at 1800

Feel free to post this to your own blog, website, Facebook group or page.. let’s spread the word!!

Thanks, Paul!

WiFi radios

Though pricey, I’ve heard the Pure Evoke F4 has fantastic audio and a meticulously curated database of Internet streams.

This is one of the benefits of Wi-Fi radios and Internet streams: the ability to hear “local” stations–many of which used to broadcast on shortwave–from all corners of the globe.

I’m seriously considering purchasing a Wi-Fi radio for my wife to make it a little easier for her to listen to Internet streams in her office.

I’ve been looking at the C.Crane CC WiFi radio, the CC WiFi 2, the Grace Digital WiFi Music Player and the (much pricier) Pure Evoke F4 which my buddy, John Figliozzi, so highly recommends.

Any suggestions and recommendations are most welcome.

The Heathkit Explorer Jr. (Image Source: Heathkit)

Yes, the legendary Heathkit company is back and their first kit is a simple Tuned Radio Frequency (TRF) AM/mediumwave analog receiver: the Explorer Jr.

I knew Heathkit was back in business and under new management, but hadn’t heard any updates as of late. Their president, Andy, just sent a message to the “Heathkit Insiders” group explaining what the team has been up to:

“We’ve designed and developed a wide range of entirely new kit products. We authored the manuals for these kits, complete with the beautiful line art you rely on, preserving and respecting our iconic historic Heathkit style. We developed many new inventions and filed patents on them. We relocated Heathkit, and set up a factory, and a warehouse, and offices, in Santa Cruz, California, near Silicon Valley. We built the back office infrastructure, vendor and supply chain relationships, systems, procedures, operations methods, and well-thought-out corporate structure that a manufacturing company needs to support its customers, to allow us to scale instantly the day we resume major kit sales. All this effort enables us to introduce a fleet of new kits and helps ensure Heathkit can grow, prosper, and continue to bring you great new products for a very long time.”

The Insiders’ message goes into much more detail–I would encourage you to contact Heathkit about joining this group.

The big news in this message was the launch announcement of the Explorer Jr. kit which can be ordered from their website now. The price is $149.95 plus shipping. Heathkit anticipates a 30-day shipping time for the first set of orders.

Here’s a description of the kit from their website:

(Source: CNN Money via Andrea Borgnino)

It turns out that radio still gets results.

Amid all the changes in television and digital media, a report from Nielsen released Tuesday found that radio’s nationwide audience reached an all-time high during the second quarter of 2015.

According to Nielsen, about 245 million Americans ages 12 and up used radio during the that span.

It was a continuation of an upward trend for radio, which has seen its national audience swell to record highs in each of the last two years. In the first quarter of this year, radio eclipsed television as the country’s top reaching medium.

Continue reading on CNN.com…

While browsing the front page of Universal Radio recently, I noted that the AOR AR-Mini B handheld communications receiver is currently on sale.

This surprised for two reasons:

1. I thought the AR-Mini B was discontinued.
2. This receiver used to sell for about $259 US.

I contacted Fred Osterman (President of Universal) for more details.

Fred informed me that, a couple of weeks ago, AOR USA announced the availability of the model once again. He noted that the units arrived from AOR JAPAN to AOR USA last week and they are now in stock.  Fred seemed as surprised as I was that the Mini B resurfaced.

He confirmed that AOR have these in quantity–they’re not simply units discovered in a warehouse corner somewhere.  They could be surplus from a large special order.

The AOR AR-Mini B is not a perfect receiver, but at $159.95 it’s a pretty good value for a very rugged, water-resistant receiver that puts much of the radio spectrum in your pocket (100 kHz to 1299.995 MHz).

If you’re tempted to purchase the AOR AR-Mini B, check out this review by Larry Van Horne (PDF) and this review by Dave Zantow first.

I have two of the Sony SRF series pocket AM/FM radios: the grey SRF-59 and the clear SRF-39FP.

The venerable SRF-59 has long been one of the least expensive, quality analog AM/FM receivers on the market. I originally purchased one new for $14.95 US including shipping. Here’s a short review I made of the ’59 several years ago.

The Sony SRF-39FP (click to enlarge)

The SRF-39FP–the model with the clear case–was specifically designed by Sony radio for the prison market.

A couple years ago, someone on eBay had a lot of Sony SRF-39FP units on sale–I jumped at the opportunity to buy one new-in-box for $20 US. The entire lot of SRF-39FPs sold in a matter of hours. Indeed, the ’39FPs were so popular, by the time I prepared a post for the SWLing Post, the seller had already sold out. (I’m kicking myself for not buying at least one extra–!)

While most ultralight radio enthusiasts would give the SRF-39FP a performance edge over the SRF-59, they’re essentially the same radio–especially if you tweak the SRF-59 like my buddy Dave Richards did.

The Sony SRF-59 (click to enlarge)

Several weeks ago, while Steve researched the reason he was hearing shortwave broadcasters on his SRF-59, he also discovered that the SRF-59 had been discontinued and selling in many places for three or four times the original price.

He found one vendor still selling the SRF-59 for $14.99 plus shipping. I placed an order with this vendor over a month ago, but still haven’t received the product because the vendor hasn’t taken delivery of the final batch of units from Sony. I’m in contact with this vendor and when/if the units are received in stock next week, I’ll post an update here on the SWLing Post (if interested, follow this tag).

If you’re in the market for a Sony SRF-59, here are a few places you may find one new or used:

• Amazon
• eBay
• Universal Radio

(If you know of other good suppliers, please comment!)

The SRF-39FP has a clear housing which is meant to prevent prison inmates from using it to smuggle contraband.

If you would prefer the Sony SRF-39FP, the only source I know of is eBay. When one becomes available, it typically sells for $45-50 US.

Click here to search eBay.

To be clear: while the SRF-59 is an exceptional ultralight receiver, $45-50 US would certainly place it in a price class with other excellent ultralights.

The Sony SRF-18

In reference to our post about the Sony SRF-39FP and SRF-59, SWLing Post reader, Peter, writes:

The Sony SRF-S84

As usual a very interesting post.

I sold most of my collection of receivers some years ago but I’m still interested in AM DXing and especially ultralight DXing (thats why I have three SRF59).

May I draw your attention to other receivers as well?

The famous CXA1129N chip has been built into the SRF-S84 and into the SRF-18 as well. I use the SRF-S84 during sports. As the ferrite rod is even smaller than in the SRF-59 AM reception is a little bit less sensible but FM shines with mega sound.

The SRF-18 is my favorite travel radio!! It runs endlessly on two AA-cells, has built in stereo speakers, audio-in and audio-out, a rather large dial which is easy to use and due to a larger ferrite rod it is very very sensitive on medium wave.

SRF-S84 on Amazon

SRF-18 on Amazon

Best regards from Germany

Peter Oden

Thank you, Peter! Perhaps the SRF-18 can take the place of the SRF-59 as an affordable MW ultralight that is still in production. The Amazon price for the SRF-18 is $32 US–quite affordable. While I don’t need another ultralight, that price makes it very tempting.

The SRF-S84 reminds me of a super compact radio I used to sneak into my fifth grade class. I would listen to the radio during class by concealing the receiver in an interior jacket pocket and snaking the earphone cord through my sleeve. I would then rest my head on my left hand where the earphone was conveniently located.  Somehow I never managed to get caught.

While I’m sure my education suffered a little that year, it still makes for good memories!

In reference to our previous posts about the Sony SRF-59 ultralight receiver, SWLing Post reader, Bill Mead, writes:

“As someone who doesn’t normally open the backs of radios, this is my mod on my ultralight. All it takes is a bit of electrical tape to hold the belt clip on the loop.”

That is, indeed, a brilliant and simple mod. The SRF-59 inductively couples to the loop antenna, so no soldering is needed; simply tape the belt clip to the loop, making sure the position is convenient for tuning the SRF-59 and the loop’s capacitor.

You can find passive loop antennas ranging from $19 to $50 US. The Grundig AN-200 and the Terk AM Advantage are two models currently on the market. Here are a few places you can check prices:

Grundig AN-200:

• Universal Radio ($19.99 at time of posting!)
• Amazon.com (who also sells the same antenna branded as the Kaito AN-200)
• eBay.com

Terk AM Advantage:

• C.Crane
• Universal Radio
• Amazon.com
• eBay.com

Many thanks to former VOA correspondent and noted DXer, Dan Robinson, for the following guest post:

A Late Summer Visit to Howard Mills’ Radio Restoration

-Dan Robinson

The end of summer is a wistful time, as we begin to mourn the passage of warm days and anticipate the arrival of autumn.

For those of us in love with shortwave, even in these waning days of HF broadcasting, August brings changes in propagation that herald the approach of improved reception, thoughts of getting antennas in shape, and preparing receivers for the new DX season.

It’s also a time when Hamfests are winding down for the year — for me, it’s still great fun to attend these and see what equipment is available.

A few months ago, I and fellow Washington, DC area SWL Dave Malick took the opportunity to visit a couple of Hamfests. At one of these, in Berryville, VA, I ran across someone who over the years has become somewhat of a legend in the field of radio restoration — Howard Mills.

Howard lives in rural West Virginia, at a point about equidistant from Harper’s Ferry and Sheperdstown. That’s about an hour or so from DC and the immediate Maryland suburbs. From DC, you drive out Rt 270 to Frederick, Maryland and then up Route 15 and 340.

It’s beautiful country — on the way you pass through small towns, past farms, and in late summer, roadside stands selling huge ears of corn and about every type of vegetable, along with peaches and apples of every type and size.

Back in the late 1990’s I first became aware of Howard Mills when I brought my Collins 51J4 to him for refurbishing.   Howard is one of the few persons remaining in this country capable of going through classic tube receivers from top to bottom.

A visit to Howard is an experience everyone should have at least once in a lifetime. Restoration activities take place in the lower/ground level of his home.

Outside there are some amazing antennas, long wires, and beams which support both his amateur radio and receiver activities.
Under a porch, covered in tarps, are some of his latest equipment and parts acquisitions, from thousands of tubes to some of the rarest radios and transmitter items one may ever see.

Inside, you find a wonderland of receivers. You name it, Howard has it. In racks, there are specialized Beckman 51J4s, SP-600s, AR-88s and R-390/As, Eddystones, and others. In another room, you see some of the most beautiful, and collectible and valuable, American and foreign-made radios dating back to the earliest days.

On tables in one portion of the basement of Howard’s place, you find several R-390s in various stages of refurbishment. One, he notes (probably among his “keepers” ) was found still new in its original crate (how I would love to have that one!).

On the day Dave and I visited, the purpose was to pick up one of the most beautiful R-390s I have ever seen — a Capehart that was refurbished by Howard in 2007 and placed in a custom cabinet, complete with an easy-left-off top, similar to the HQ-180 design. This black beauty is now sitting in my shack at home.

Howard has been at it for many decades, as I said. A conversation with him is a voyage through radio history, punctuated by references to a range of major radio manufacturers. He clearly loves what he does, though one wonders how much longer he will be at it.

Howard emphasizes by the way that his work is in restoring TUBE radios — he doesn’t get into solid state. There are a few well-known receivers in his place — I noticed an ICOM IC-R72 and a JRC NRD-535– but most of what you see are the classics that we have all come to know and love.

His primary specialty appears to be the 51J series. A link to him on the Collins site notes that his main focus is on A line equipment, J series, and 32V series, but he is certainly capable on a number of models, including as I saw, HQ-180s and AR-88s (http://www.collinsradio.org/howard-mills/)

I was able to take some photos of Howard’s operation and offer them to SWLing Post readers here. At this point, Howard remains in business. He has had customers from all over the U.S. and I assume around the globe.

For each refurbishing job, Howard provides an extensive print out of every single modification and component replacement he does, along with the results of sensitivity and calibration tests done for each set.

Please do note that Howard makes clear that basically as long as it takes him to refurbish a radio — is as long as it will take.   If you give him one of your radios, you basically agree to it being with him for several months if not longer. He does have a backlog.

Things like sandblasting front panels for R390s (I am not certain to what extent he does this himself or out-sources this particular aspect) also takes time.   And the detail with which he approaches a breakdown of an R390/A, evidenced by the sets I saw in process, is quite extraordinary and time-consuming.

Howard gets mostly superb reviews from those who have used his services. If you look him up on the Internet, and he has time for you to visit, it’s an experience you will always remember, though it’s not that I would suggest a crowd descend on him.

Hope everyone enjoys the photos — I had intended to get this article to Tom much sooner than October. Keep in mind, of course, that though Howard is one of the last to do this kind of work, there are a few others, including Chuck Rippel in Virginia.

We are indeed lucky to have anyone still doing this work. We know they do it not just as a business, but out of a love for this wonderful old equipment.

Photo gallery

Many thanks, Dan, for taking us on this virtual tour of Howard Mills’ collection and workshop!

Your Capehart R-390A is absolutely gorgeous; Howard, no doubt, brought it back to mint status through loving, considerate restoration. What a great addition to your collection, Dan.

Thank you, again,  for sharing your guest post.

Many thanks to several SWLing Post readers for sharing a link to the following investigative story from Reuters. I’ve included an excerpt below–you can read the full article, and watch a video at Reuters online.

(Source: Reuters)

In August, foreign ministers from 10 nations blasted China for building artificial islands in the disputed South China Sea. As media around the world covered the diplomatic clash, a radio station that serves the most powerful city in America had a distinctive take on the news.

Located outside Washington, D.C., WCRW radio made no mention of China’s provocative island project. Instead, an analyst explained that tensions in the region were due to unnamed “external forces” trying “to insert themselves into this part of the world using false claims.”

Behind WCRW’s coverage is a fact that’s never broadcast: The Chinese government controls much of what airs on the station, which can be heard on Capitol Hill and at the White House.

[…]A typical hour on most stations begins with a short newscast that can toggle between China news and stories about violent crimes in the United States. Besides the overtly political coverage, topics range from global currency fluctuations and Chinese trade missions to celebrity wardrobe analysis and modern parenting challenges.

[G&E president and CEO James Su] declined to describe how he makes money when most of the U.S. stations air virtually no commercials. He also declined to say how he got the money to finance his radio leases and acquisitions.

His stations, Su said, offer the American public an alternative viewpoint on Chinese culture and politics. He has “no way to control” what CRI broadcasts on the stations, he said, nor is he part of any plan to spread Chinese propaganda.

“We are only telling the unfiltered real news to our audience,” he said.

On Oct. 29, WCRW carried a program called “The Hourly News.” Among the top stories: Senior Chinese and U.S. naval commanders planned to speak by video after a U.S. Navy ship passed close by China’s new artificial islands in the South China Sea.

Washington and its allies see the island-building program as a ploy to grab control of strategic sea lanes, and the Navy sail-by was meant to counter China’s territorial claims.

WCRW omitted that side of the story.

The admirals are holding the talks, the announcer said, “amid the tension the U.S. created this week.”

Read the full article at Reuters online…

I’ve been traveling along the coast of South Carolina this week, and on Thursday, I found myself in the historic town of Conway, South Carolina. I parked downtown and strolled into the past via Papa’s General Store, a small local store with a lot of merchandise––and a lot of charm.

While browsing a display of antiques, I happened to notice a vintage radio perched on a high shelf. Here’s what caught my eye:

I asked, was the radio was for sale? And, indeed, it was. One of the sales clerks pulled it from the shelf, dusted off the top, and read the price: $74. I noted that it was a West German Telefunken receiver.  I asked the clerk, Chris,  if it worked, and he confirmed that it did; it belonged to his uncle, who had clearly taken very good care of it.

Chris allowed me to plug it in, turn it on, and tune in a couple of local stations…The Telefunken produced beautiful audio without even the slightest hint of a hum. Chris was pleased that I appreciated the radio, and sincerely wanted me to take it home, so he lowered the price a bit further.  I agreed, and purchased it without hesitation. Just couldn’t help it…

Chris behind the counter with his uncle’s classic Telefunken.

The Telefunken Superheterodyn Caprice 5451W covers the AM/mediumwave band and FM. It’s a tube radio produced in the early 1960s in West Germany, and is now the only tube-based radio I own that covers the FM band.

Of course, I was very eager to get the Telefunken on the air, so that afternoon I headed to our balcony overlooking the Atlantic, tuned around a bit on the mediumwave band…and was simply amazed at all it could receive.  I picked up my smart phone, and with it made a very short recording of the Cuban station, Radio Reloj, on 820 kHz:

My smart phone’s microphone doesn’t begin to do the Telefunken’s rich audio justice, but you can clearly hear Radio Reloj’s ticks and “RR” in Morse Code at the top of the minute (indeed, if you’re listening with headphones, you may also hear crashing waves in the background). Something nearby generated a lot of RFI right on frequency, too , but the rest of the broadcast band had a surprisingly low noise floor.

I also spent some time with the Telefunken on the FM broadcast band; with a simple wire antenna, this worked wonders.

In my humble op, the audio the Telefunken produces is simply beautiful.  And so, I’ve got to add, is this vintage radio. See for yourself.

SWLing Post contributor, OWL, writes:

It seems that Tecsun has a new large portable in line.

Someone posted a photo of a new Tecsun product catalogue which shows a new model S8800.

The Tecsun BCL-3000 for comparison.

Apparently it uses the housing of BCL3000 [see above] and is multiple conversion (so a PL880 inside?), DSP based with separate LSB/USB and 10Hz minimum tuning step, and comes with a remote control (for direct frequency input?). Two 18650 batteries are used.

Photo source: http://bbs.tecsun.com.cn/ via OWL. Click to enlarge.

Photo source: http://bbs.tecsun.com.cn/ via OWL. Click to enlarge.

[Here’s a] link to the post in Tecsun’s web forum:

http://bbs.tecsun.com.cn/0002.asp?open=730351

Many thanks for sharing this find, OWL! This is a very curious development from Tecsun.

I can imagine why Tecsun is re-using the BCL-3000 (a.k.a. Grundig S350DL) body–not only is it roomy inside, but it’s proven to be a popular large portable form factor over the years. Of course, since this is an existing chassis design, design/development costs will be minimal.  If Tecsun is including a remote, I’m sure OWL is correct: it’ll aid with direct frequency entry. The S-8800 will be the first portable shortwave radio with remote control I’ve seen in many years.

If audio is anything like its predecessors, I would expect rich fidelity from the built-in speaker. In terms of performance, though? This is a completely different receiver than the single-conversion BCL-3000, so only time will tell.

Regarding the new DSP version of the Degen DE1103, SWLing Post contributor, Andi_84, writes:

I’ve opened [my Degen DE1103] and checked the semiconductors inside.

It’s definitely based on a Silicon Labs chip (Si4735-D60).

1) Display PCB
Valence Tech AP651 “LCD AND KEYBOARD CONTROLLER”: http://www.valencetech.com/products.php?prodID=ap651&type=ics
Datasheet: http://www.valencetech.com/doc/AP651/DS_AP651-Rev0.1.02.pdf

2) Main PCB

a) Silicon Labs Si4735-D60 “AM/FM/SW/LW Radio Receiver IC”: http://www.silabs.com/products/audio/fm-am-receiver/Pages/si473435.aspx
-> Chip is even capable of RDS, but it’s unfortunately not implemented in the DE1103
And, FM range covers down to 64MHz, while the DE1103 goes only down to 76MHz
Datasheet: https://www.silabs.com/Support%20Documents/TechnicalDocs/Si4730-31-34-35-D60.pdf

b) ST Micro STM8L152C6T6 “Ultra-low-power 8-bit MCU with 32 Kbytes Flash, 16 MHz CPU, integrated EEPROM”
Datasheet: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00240181.pdf

c) China Hua Jing Electronics CD1622CB “110mw X 2 Dual-channel audio power amplifier”
-> Looks like a “chinese version” of the Sony CXA1622M
Datasheet: http://www.datasheet.hk/view_download.php?id=1039877&file=0024%5Ccd1622cb_203207.pdf

d) LM358 “Low-Power, Dual-Operational Amplifiers”
Datasheet: http://www.ti.com/lit/ds/symlink/lm158-n.pdf

Photos

The following photos are courtesy of Andi_84. Please click the image to enlarge.

External and unboxing

Internal and circuit board

Many thanks, Andi!  These photos are excellent and certainly give us more insight into the new Degen DE1103 design.

I’m very curious how this new DE1103 compares with other DSP portables on the market.

SWLing Post contributor, James Patterson, has recently restored a Sony ICF-5800H. James sent me a few photos and I decided to post them here.

I absolutely love the design of Japanese analog radios from this era. They have signal meters, large backlit dials, carry straps, and proper large controls–buttons, switches and knobs–that can even be operated when wearing gloves in the winter.

Great receiver you have there, James!

When I discovered that Degen had recently refreshed the receiver design of the DE1103, I was intrigued, to say the least. The original DE1103 sported some serious performance for a sub-$100 receiver.

The 2015 model of the Degen DE1103 implements a DSP chip (the Silicon Labs Si4735-D60).

Yet I was on the fence about purchasing the new DE1103. Why? In truth, I never fell in love with the original DE1103. While I appreciated the 1103’s unique analog-style digital display, I never got used to its quirky ergonomics. Degen had quality control issues, too: I had to return two faulty units before getting one that worked as advertised (incidentally, I had a similar problem with the Kaito KA1102).

Then last week, SWLing Post reader, Ron, contacted me. He had purchased the new DE1103 from Hong Kong-based eBay vendor Bigbargainonline.

Ron kindly provided the SWLing Post with his impressions of the DE1103, as follows:

Performance is roughly on a par with the earlier dual conversion version. This one is just as hot, but no hotter.

If you were thinking a GP5 on a bigger ferrite bar, yes…and no.

There is one major gripe…[this unit] will not remember frequencies set with the BFO on, like the earlier dual-conversion version did. Instead you have to turn the BFO on for each memory frequency [for which you] need it.

One thing [I] noticed right off was the almost complete lack of AGC “pumping” on CW and SSB that all earlier versions had (yay!) but this plus comes at the cost of having the BFO “remembered” in memory.

Zero-beating (or centering) the BFO to null on WWV and local AM stations to check alignment was…strange. At null beat the BFO seems to quit for a second. It is fine
either side of zero beat, however.

This is doubtless due to Tecsun’s adapting the Silicon Labs IC to a full range BFO like this. Recall the same IC in the GP5 features Upper and Lower selection on CW/SSB.

This 1103 DSP version also has the GP5’s slight tuning mute, not a problem.

But for ease of operation in CW/SSB mode, the GP5 is [much] better IMO.

Ron also notes that he wasn’t pleased with the DE1103’s longwave performance and didn’t feel the mediumwave and shortwave reception was an improvement on the original DE1103.

He decided that he would sell this DE1103 and gave me first dibs, so I bit the bullet. I was eager to compare the new DE1103 with some of the other DSP-based portables in my collection. Ron dispatched the DE1103 immediately–it arrived a few days ago, but I didn’t have a chance to test it until yesterday.

I took the Degen DE1103 outside, sat it on the tailgate of my truck and put it on the air…

I tuned around the mediumwave band and picked up all of the local benchmark stations. Same with FM. So far, this tuning confirmed Ron’s assessment of the DE1103: it didn’t surpass the original.

But the shortwave bands were a different story.

As I tuned around the HF bands, the DE1103 seemed to receive quite a lot signals.  But in most instances, I could hear local AM broadcasters bleeding in, as well. Indeed, imaging was prevalent across the shortwave bands–the receiver was obviously being overwhelmed by a local broadcaster.  Unfortunate.

Could strong interference account for this? While there are local AM broadcasters around, they’re not exactly “blow-torch” stations. Indeed, I’ve never had overloading issues with other shortwave portables I’ve used in the same location–not even with my Kaito WRX911!

Imaging was prevalent on the DE1103 when it was tuned to pretty much any audible shortwave broadcaster.

Here’s a video of the Degen DE1103 tuned to the Voice of Greece on 9,420 kHz:

What you’re hearing in the audio is a local broadcaster bleeding in. Note that when I tune off-frequency, no imaging is heard.

Wondering if something had changed locally–and just to be fair–I pulled out my Sony ICF-SW100 and sat it next to the DE1103. The Sony had no issues.

This time, I tuned to WWV on the 19 meter band and compared the two receivers:

As Dan Robinson expresses it, the ICF-SW100 “wipes the floor” with the DE1103. There’s no hint of overloading in the SW100.

My buddy, Ron, is clearly a keen radio reviewer; obviously he didn’t hear overloading on the shortwave bands where he tested the rig, else he would certainly have mentioned it. The location where I tested the DE1103 does have some local broadcasters in the area, but no clear channel or high-power stations; in short, there’s no likely interference within a ten-mile radius to account for this debilitating performance problem.

Too bad…!

Obviously, the new DSP version of the Degen DE1103 is especially prone to imaging on the shortwave bands. In fact, it’s the only receiver I’ve ever tested that has overloading issues at this testing location (where I tested the original Degen DE1103, by the way).

My assessment? Avoid the new Degen DE1103.

A much better receiver with SSB for roughly the same price would be the venerable Tecsun PL-600 ($89.99 at Amazon and $89.95 at Universal Radio). If SSB reception isn’t necessary, you might also consider the CC Skywave or the very affordable Tecsun PL-310ET.

Many thanks to SWLing Post contributor, Jeff McMahon (at the Herculodge), who writes:

I upgraded my Sangean U3 with a male to female iMBAPrice 6 foot stereo audio extension cable 3.5mm, which I plugged into the U3’s auxiliary port.

The U3’s small stub of an FM antenna really needed some extra oomph. Now my U3 is picking up all my favorite stations, including the problematic KPCC 89.3 in Pasadena.

AM is as great as always. The sound is crystal clear on AM and FM. If this radio weren’t so big, I’d buy two more for the kitchen and my bedroom, but will have to be content to have one for my gym/office radio.

Thanks, Jeff! I might have to consider the Sangean U3–I hope a reader will let me know if one goes on sale.

Like Jeff, having a radio that not only performs admirably, but that can also withstand the attention of my kids, may be a great investment over the long-term! I’m glad such a simple addition to the U3 means that you can now hear your favorite Fm station, Jeff!

Now if Sangean only made a shortwave version of the U3–!