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Hi there, here is part two of my original post containing various reception videos for the amazing Tecsun PL-310ET pocket shortwave receiver. I continue to be amazed at the sensitivity and selectivity of this rather modest and diminutive receiver, particularly at it’s price-point of around £40 in the UK and less elsewhere! Here is the second half of the reception videos, with some nice signals from Brazil, Guinea, Ethiopia, Swaziland and India. You might notice that some of these catches involve the use of a 240 metre (approx.) length of barbed wire fence! I’m not sure how beneficial the electrical properties of the fence were, probably somewhere between not great and not good lol, but some pretty decent DX was had with the PL-310ET attached to it via the external antenna socket and a crocodile clip!
The barbed wire fence extends almost to the treeline on the horizon; about 240 metres
I hope you enjoy this set of reception videos, they certainly help to demonstrate the great performance of the PL-310ET and in addition of course, it’s ability to handle large antennas quite well. Embedded videos and text links follow below. Lastly, there are now approaching 1,200 reception videos on my YouTube channel Oxford Shortwave Log and I would like to take this additional opportunity to thank everyone for their support, friendship and advice. In the meantime, I wish you all a very Merry Christmas, a Happy New Year and excellent DX!
Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.
Many thanks to SWLing Post contributor, TomL, for the following guest post:
“Car Shack” radio listening
by TomL
My car is an unusual place to listen to shortwave radio but has interesting possibilities. Due to the obscene noise at my home QTH, I decided that I must try something away from this unfortunate situation. So I took my homemade 14-inch loop antenna and outfitted the appropriate ancillary equipment with DC power packs. My trusty Sony ICF-2010 is the radio “vehicle” to “drive” this experiment (LOL). And, seriously, this is a way to show the public that it is not that hard to have a portable radio listening setup. Believe me, if I can do this, anyone can!
The basic ingredients are pictured here with some variations (see text):
Wellbrook amplifier powered by DC power pack of 10 eneloop AA batteries
KIWA Broadcast band (mediumwave) inline filter
Palstar preselector (active antenna) plugged into car cigarette lighter
Sony 2010 connected to a second DC power pack
Sony ICD PX333 digital recorder
Sennheiser earbuds
7 inch Samsung tablet and 4G MiFi device to do internet schedule lookups
Illustration SEQ “Illustration” 1: Car Shack in operation.
An important finding was that anything that has a cheap IC circuit to regulate and/or convert DC power can be extremely noisy! The pictured 16000 maH lithium brick would initially be quiet but after a while it would start spewing noise all over the bands. Power cycling it sometimes helped but I decided that it is too unpredictable. Also, converter cables that convert 5V to 12V for devices needing 12V also produce overwhelming amounts of noise. Even a small 5V USB converter plugged into the cigarette lighter makes a modest amount of ubiquitous noise. I am ditching the lithium power pack and converter cables and any cigarette lighter adapters!
So, the main radio power pack will use the internal Sony battery comparment consisting of nine 2700 maH NiMH AA’s inside three D-cell battery holders that can each hold 3 AA batteries in parallel. This boosts the capacity to around 8100 maH for a modest cost (I already have NiMH chargers and the 4.5V requirement is not too high for the batteries in question). Pictured are examples of a single D-cell AA holder of which I bought 12 and the silver-top Powerex 2700 maH AA’s from fleaBay. The total voltage is slightly low (3.6V) but the Sony 2010 still works at a slightly lower performance (received signals are slightly weaker). I run the Sony on Local sensitivity and crank up the Palstar active antenna to compensate.
In a further quest for clean, portable DC power without noisy IC chips, I have been researching lithium batteries and it is quite a large amount of work to sift through all the variables. The Palstar active antenna and the Wellbrook amplifier both use external connections of 12V, 2.1mm (+ tip) plugs. NiMH is not going to cut it, too many needed and getting too heavy. Amongst the variables are things like:
Using a proper charger and not leaving it unattended or it could burn down your house
Chinese fakes being sold by the zillions that look exactly like the real thing
Initial cost being higher than current NiMH
Avoiding 1.5V step down batteries with noisy step down converter built-in
Learning the new terminology for sizes: AA = 14500 = 14mm diameter & 50mm length
Learning the differences between type of lithium: Lithium, Li-ion, LiFePo4, IMR, etc.
The difference between protected vs. non-protected batteries
How to avoid discharging the batteries too much which could render them completely useless (not just usage but also NON-usage as well)
How to physically handle Lithium batteries to avoid shock and temperature extremes
Learning how to compare maH’s of lithium to NiMH batteries
Finding out that most top rated 14500 Li-ion batteries are too long to fit into AA battery holders without risking damage to the protection PCB mounted at the bottom of the battery
and the list goes on and on…..
Here are some of the web pages I read to try to understand this technology:
So, to cut to the chase, I have decided to order this one from XTARDirect because:
I can order from a USA distributor who orders from the factory in Shenzen China
The price is very reasonable for “protected” lithium ion batteries
They actually should fit into typical AA battery holders without damaging it
Illustration SEQ “Illustration” 2 XTAR 14500 800 maH Li-ion
They are not the highest rated in terms of capacity, load drain, amp surge ability, etc., but they seem to have enough positive statements from users that indicate it gets the job done. Since I don’t have the lithiums yet, I am using some temporary 10-cell AA holders with good old Eneloops – good enough for now. And I am buying this discontinued charger at a discount to recharge lithiums:
Illustration SEQ “Illustration” 3: Nitecore i4 original version
I will make two power packs made from these items pictured. The wire is fragile so I super glue the insulation directly to the DC power plug housing (avoiding getting any glue onto the bare wire inserted at the back). I will use three sets of lithiums (9 batteries) plus one set of Eneloop Pro’s (3 batteries) per power pack in the aforementioned parallel AA holders.
Illustration SEQ “Illustration” 6: 2.1mm x 5.5mm DC power plug.
Other items of note: The umbrella stand is optional since I found I like to move the antenna around and even tilt it to get slightly better directional signal. More importantly, I found that if I cut the Sony 2010 sensitivity from DX to Local, and then crank the Palstar preselector’s amplifier, I get a cleaner sound with less background noise. Also, the KIWA mediumwave filter is essential due to overloading.
One of my favorite stations is Radio Educacion (XEPPM) on 6185 kHz. A 1 kW station near the foot of Vulcan de Guadalupe in Mexico City, it is so weak that I almost never hear it and their wonderful selection of music representative of regional & cultural heritage. It is also 1675 miles distant according to Google Earth. Now, if I want to bother, I can go out and listen in my car at locations less noisy than home. So far, the safest places have been the parking deck at work (only two stories high) and the local grocery store parking lot. What I would really like is a very tall parking deck whose owners let me stay up on top long into the evening without harrassment (not sure I want to risk security personnel questioning me about the strange contraption and equipment – paranoia reigns these days)!
Sample of XEPPM, moderately good propagation from the work location:
Unexpected reception happens with this experiment. I mounted the antenna in the back, away from the engine and against the rear side window. Was traversing the local restaurant drive-through lane to get a hot dog, and turning the corner next to the long empty brick wall, the reception became dramatically stronger and clearer! Apparently, the brick wall blocked some interference as well as enhanced the signal coming from the Northeast. You can hear the effect starting at 25 seconds into the recording of RRI:
Also, not recorded from a previous evening at the grocery store location, 6135 kHz Radio Santa Cruz in central Bolivia, a 10 kW station playing Spanish rock music and a clear ID near the top of the hour.
More experiments to do, like
Mount the antenna as high I as dare with PVC pipe (too cold out now and I would rather not open any windows but I am itching to mount the umbrella stand and antenna on a 3 foot PVC pipe on the roof of the car, the increase in received signal strength is significant)
A bigger backpack to carry all this equipment away from the car
If Elon Musk has his way and builds the Gigafactory (and competitors follow suit), there could be many more experiments with lithium type batteries in the future
Perhaps get an SDR and cheap laptop computer to replace the Sony radio
PS: I found out that the three-AA battery holders do not make contact at the (+) tip of the XTAR lithium batteries I purchased. I just gently lifted up the contact inside the battery holder to allow it to reach the battery tip, that’s all that is needed. Whatever you do, do not put an extra piece of metal inside the battery holders! I accidentally damaged the outside skin of two of the batteries with a common piece of copper metal and the batteries immediately started to get HOT. I took them out as soon as I could and the batteries cooled down. So, don’t use any extra metal surface inside the battery holders; lithium batteries do not tolerate any kind of short circuit!
Cheers from Noizey Illinoiz,
TomL
Thank so much, Tom, for sharing your experiences and your ongoing experiments! Lately, I’ve been doing NPOTA activations with a portable loop antenna on top of my vehicle. I completely understand what you mean about getting strange looks from passers-by! We look forward to hearing about your future experiments fighting RFI.
The past few days, I have noticed higher than usual noise levels, generally on the lower frequencies, and particularly on the longwave band, including the 285-325 kHz DGPS band, where I run nightly SDR recordings, to later process the data and decode and detect DX DGPS stations using my Amalgamated DGPS app.
Thinking back to what new electronics devices have been added to the house, two came to mind, a new cable modem, and a new ethernet switch. The switch is up here in the shack, so it seemed to be a likely candidate. The switch is a D-Link DES-1008E 8-Port 10/100 Unmanaged Desktop Switch. It uses a mini USB port for power, using either the included AC adapter, or power from a USB port. When I installed it, I decided to not use the AC adapter, but rather a USB port on my UPS, figuring it was better to not add yet another potentially noisy switching power supply to the mix.
The test was easy, I just unplugged the power to the switch. Sure enough, the noise vanished. Great, the switch is a RFI generator. Or is it? As another test, I plugged it into a port on a USB hub. No noise. Hmm… so it seems that the noise is indeed from the USB port on the UPS. I did not notice any increase in the noise floor when I got the UPS a few months ago, but It’s something I should look into again, just to be sure. The UPS is a CyberPower CP1350PFCLCD.
Here’s a waterfall from the SDR, showing the DGPS band, 280-330 kHz. You can see where I changed the power to the switch from the UPS USB port to the USB hub, the bottom part of the waterfall is when the switch was still powered by the UPS (click to enlarge it):
I still have a noise source just above 305 kHz to hunt down.
Update
I decided to see what I could do to improve things, and reduce the noise floor.
Here is the baseline, after no longer powering the switch from the UPS:
First, I relocated the AFE822 away from the computer and rats nest of assorted cables behind it, powered from an HTC USB charger:
The squiggly noise around 305 kHz vanished!
I then switched to an Apple USB charger / power supply, as their products tend to be a bit better made:
Another improvement, the overall noise floor is a bit less now.
But can we do better? I then switched to an older USB hub for power to the AFE822, that I thought might be better filtered:
I then changed to a linear supply plugged directly into the AFE822. I don’t notice any obvious improvement? Maybe it even looks like a little more noise? Difficult to tell. You can see a DGPS station popped up on 304 kHz while I was switching things around, between the last two tests, it was likely Mequon, WI.
Thank you for sharing this, Chris! I find a wideband spectrum/waterfall to be such a useful tool for tracking down sources of noise. Not only can you “see” the noise, but you can measure its bandwidth and identify what portions of the dial it affects.
Hi there, a few weeks ago I posted a couple of medium wave DX catches with the Elad FDM DUO and newly constructed 200 metre Beverage antenna. Since then (and following my trip to Brazil) I have uploaded several more catches, some of which I would like to share with you. It has become evident that the Beverage’s low-gain but high SNR properties resulted in a huge increase in the sensitivity of my entire set-up and as a result. I have achieved numerous personal firsts on the medium wave band, coupled with many other signals that I can only describe ‘best-ever reception’. If nothing else, this endevour has underlined the importance of utillising the best antenna possible for your particular circumstances. We’ve all read at some point, how, in many respects, the antenna is more important than the receiver – and these catches demonstrate how absolutely true that statement is. All of the reception videos were captured using the Elad FDM DUO running on a home-brew battery-pack and connected to the Beverage via a 50 Ohm input transformer.
Below is the first set of reception videos, most of which are signals from East Coast of the United States. However, there is also an absolutely booming signal from WGIT Puerto Rico into my QTH in Oxford UK. Part 2 will follow almost immediately, but in the mean time thanks for watching/listening and I wish you all great DX!
Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.
Hi there, here is a summary of the first half of tests comparing the Sony ICF-2001D against it’s replacement the ICF-SW77. Both receivers are widely acknowledged as being amongst the best shortwave portables ever made, but how close are they in performance? Is there a clear winner after the first 8 reception tests? I hope you enjoy the summary video. Links to the first half of reception tests follow again, below, whilst the second half will follow in a separate post. Thanks and good DX to all.
Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.
My VERY NOISY Sony CRT TV has gone to the great electronics recycling bin in the sky thank goodness. But I still have a MFJ-1026 here and need to use it when the neighborhood gets noisy. Intermittent power line noise is the main issue these days for me.
[Note that] my Monitoring Times review from April 2007 on the MFJ-1026 (and 1025 model without the preamp, but is best to have it) is still available here :
I still power it with a analog REGULATED Jameco 170245 12 volt (1 amp) ac adapter.
Last batch I purchased a few years ago were still 100% clean and analog regulation. As I have covered in the past, SOME of Jameco excellent REGULATED AC adapters have gone to using switching regulator devices inside (and these no longer clean for any radio use).
DX Engineering is about to come out with a improved version of the premium priced NCC-1, called the NCC-2. Mid late November Delivery ?? Never had our hands on one the pricey NCC-1 critters as the MFJ gets the job done for us (let alone affording it).
Many thanks to SWLing Post contributor, DanH, who writes:
I read this news item today. AT&T has a new approach to broadband over power lines called AirGig. Supposedly, this technology will avoid RFI issues encountered with previous BPL technologies. This shouldn’t be an issue in my neighborhood where power lines are underground. Underground utilities still have RFI issues. My next door neighbor’s AT&T high speed internet swamps out all nearly all shortwave signals below 4.7 MHz within radius of 30 feet from the connection box.
