Saturday, December 9, 2017

The SANGEAN PR-D6, Sony fence DXing, and Summer in September

The Sangean PR-D6, a portable AM-FM radio that runs on 4 AA's and puts out nearly one watt of audio -- and it has good performance on MW/AM, too. I kept the plastic protector over the dial for a while as I started using the radio outside while brushcutting... I didn't want to get it all scarred up so soon after getting the radio... The plastic has since been removed. :-)

I first learned of the Sangean PR-D6 portable radio about six months ago, on a radio forum I read a lot. Apparently a famous radio DXer/blogger reviewed this Sangean radio a while back and gave it two and a half stars.

Apparently Sangean decided to market a small AM-FM radio with good performance and great audio -- the kind of portable you can carry around the house, or take on camping trips. Something that is tough and reliable. They achieved that goal with the PR-D6.

I saw one for sale at Fry's electronics box store priced about 3-4 dollars off (it was a return or a demo) and decided to bite. I was pleasantly surprised. The Sangean PR-D6 is a good little radio. It has a couple minor glitches, but for emergencies, or for taking out in the yard, or taking from room to room in the house to stay tuned to a program or football game or whatever, it gets the job done very well.
The radio that is permanently installed in my car is long shot -- the PR-D6 works well enough on FM and AM to listen to local stations while driving.
First off, the radio is small. It's larger than a pocket radio, but smaller than your average portable AM-FM radio -- about the size of a thick paperback book. Second, it has a fairly good sound: with tone controls and two audio chips, including the final audio chip being rated at over one watt (the speaker is rated for over two watts), the PR-D6 can put out a good sound.

It's small enough to carry around in a backpack, or to toss into a luggage bag.

The PR-D6 runs on four AA batteries. It will also run off of an older style 6 volt wall wart -- so long as it has a negative tip (as most Sangeans and Panasonics have historically used: some newer Sangeans -- like the famous PR-D5 -- have positive tip wall warts -- so be careful with polarity!).

The PR-D6 is a decent DXer on the Medium Wave band. It is better than your average clock radio or Walkman, but not quite as high a performer as a Sony ICF-38, Sangean 909, Realistic DX-375, or similar radio. The IF chip used (a TA2111N/YD2111N) is a good chip but the chip doesn't have a super high gain RF amp inside it, and there is apparently no RF amp transistor in front of the IF chip -- so, like most modern portable AM radios, it's not a "TRF" design (the TA2111N does have an RF amp section -- apparently 4 internal transistors -- but it's not as high gain as some other IF chips on MW).

That said, it works well for DXing, especially on nights when the MW band is hopping. It will also work with an external loop, but you have to have the loop 3-4 inches to either side of the radio (about 10cm). It has a ceramic filter inside which works well: during the late mornings, for example, it would pick up KXTG Portland on 750 kHz when my GE Superadio III (with 4 IF filter stages) was partly covered by local KTTH 770. That's how good the selectivity is.

The ceramic filter is so good you can hear that distinctive ksssshhhh sound when tuning across a channel. The selectivity is good overall because of this: however, during the day I've gotten a station on 1170 kHz (about 90 miles away) covered by some bleedover from local KKNW 1150. At the same time, KIRO 710 doesn't cover CBU 690 from Canada, about 110 km away, so if a regional station is strong enough, it can cut through in daytime conditions.
The Sangean PR-D6 with the front off. The little chip visible in the radio just beneath the dial pointer is a secondary audio chip, a UTC4580, that drives the tone controls. If you zoom into the picture you can see the speaker is rated at 3 watts max. The main audio chip is capable of putting out a watt.

The MW/AM antenna, although it's about 90mm long, seems pretty thick, and is highly efficient. It is very directional, and nulls very well. If you are in a low signals area as I am in (I live in a 'hole', basically) -- an external loop is advisable for serious DXing. If you live in a high signals area, you may not need one to DX with the PR-D6.

On good DX nights the PR-D6 will hear most -- if not all -- of what good portables will hear. On poor DX nights, other radios (like the DX-375 or ICF-38) will pick up a few more stations than the PR-D6 (without an external loop, of course).
Here in this slightly blurry picture you can see the PR-D6's audio chip, located just beneath the tuner cap. It's the same audio chip used in the PR-D5, a UTC2025. The IF chip, a Chinese knock-off of a Toshiba TA2111N, isn't visible in this pic, and it was nearly impossible to get a pic of it as it's buried beneath the chassis of the radio here.

That said, I have heard DX on it that other, better radios receive: recently I heard WCKY 1530 out of Cincinnati, Ohio on my PR-D6, with a preacher talking beneath dominant KFBK Sacramento. It was coming in as strong on my PR-D6 as it was on my Sangean PR-D5 (a MW DX radio I have written about in other blog posts here).

ASIAN HETERODYNE ON UPPER SIDE OF 970 KHZ HEARD ON THE PR-D6
I've even heard a heterodyne from Asia on the upper side of 970 on my PR-D6 (972 kHz, probably the 1200 Megawatt station from South Korea). There was no audio, though. But hearing a het from across the Pacific shows that the PR-D6 is definitely capable of DX. The hill near where I live has slightly better MW reception than my own location, and I sometimes go shopping there. I had my PR-D6 in the car with me when I went shopping one night, and KGO 810 San Francisco came in louder than the local station on 820 kHz right next to it. I was pleasantly surprised. The PR-D6 may not quite be a Superadio, but it will pull in distant signals quite well.
A view of the inside of the PR-D6. This picture of a Clear PR-D6 kind courtesy of Sangean, from their website. In this pic you can see the main circuit board. The radio circuitry is to the left of this picture, the audio chip is somewhere in the lower center, near the speaker. The pre-amp audio/tone chip is above the speaker. You can see the MW loopstick, which isn't easy to measure but seems to be 90mm or so. The radio itself is about 160mm wide (4 3/4" high by 6 1/4" wide). If you zoom the picture, you can see that the speaker is capable of handling 3 watts. The radio itself is only capable of putting out a watt -- still impressive for a small radio.
A front pic of the PR-D6CL, the clear version, courtesy of Sangean's website.  Most of the circuitry is on one elongated L shaped circuit board. The PR-D6 is a fairly simple machine.

FULL, LOUD SOUND
The audio chip in the PR-D6, a YD2025, is the same basic audio chip that is in the PR-D5 -- a chip capable of putting out nearly a watt of audio. The YD2025, like the UTC2025 in the PR-D5, is a variant of the Toshiba TA2025, apparently a well known audio chip. The three inch speaker in the PR-D6 is possibly the same speaker used in other Sangean AM-FM portables -- fairly robust. The radio seems well designed, with and extra audio chip for the tone controls (and probably used also as a buffer amp). The tone controls work well, which are a plus. Many similar radios (my Sony IFC-38 being an example) just have a tone switch. I've never cranked my PR-D6 very high, but the speaker seems to exhibit no distortion at loud levels. 

While clipping brush and blackberries I took the PR-D6 outside to listen to a football game while doing yardwork. The PR-D6's one watt audio makes it handy for listening outdoors.

FOUR AA's LAST A WHILE IF THEY ARE ALKALINES
The radio sounds good on headphones, and if one is DXing for extended periods with the PR-D6 using headphones is probably advised, as the radio has a bit higher battery usage compared to some other similar radios -- the one watt audio chip is the reason. For example, my Sony ICF-38 is very light on batteries -- a set of AA's in a Sony ICF-38 will last more than a month. With the PR-D6, it seemed that after 20-30 hours of use the AA's were fried. I'm not sure if it was the batteries themselves, or the high output AF chip that helps eat batteries. Still, 20-25 hours of use is enough for the radio to be useful during emergencies -- just keep a couple extra sets of batteries handy, and don't crank the audio too high when the power is out for a long period of time. Or use headphones most of the time.

The most recent set of AA batteries (cheap alkalines) I put into my PR-D6 seemed to have lasted longer. So far, maybe 30-40 hours or so later, they're still working.

FM GOOD, BUT CAN ALSO OVERLOAD WITH LONGER ANTENNAS
On FM, the PR-D6 is OK. Mine came without the short rubber-duck antenna attached. The rubber duck antenna that usually comes with a PR-D6 apparently was stolen or lost in the store (hence, the reduced price). Even without the antenna it will pick up all of the local FM stations with decent signals. Terrain shadows and weak spots in the house are a bit more noticeable, but overall it's a decent take-around-the-house or yard radio for FM as well as AM.

I attached a hank of wire to the FM antenna jack, and found that the signals improved slightly but it also overloads easily -- with mine, local FM overload hash appears in blank spots in between FM stations. So I've left the antenna jack bare -- just a 4mm bolt screwed into it, in case I ever want to attach a wire that way.

Obviously, the PR-D6's strong suit is its AM performance, which is much better than expected.
I kept the plastic dial protector on the radio for a while, as I was using it out in the yard, while clipping boughs and blackberries. Here I'm listening to a Seahawks football game, in late September.

GREAT FOR CAMPING, GOOD FOR EMERGENCIES
-- KEEP A SPARE SET OF BATTERIES
Overall, at the price of around $35 for this radio, I think it is a good value for the money. Decent performers at this price range are a bit rare. The PR-D6 looks well built, and it works well. It's a simple machine and it looks like it should hold up well over time. It's probably a good emergency radio, so long as you keep a spare set of batteries. It probably will last longer with alkalines than regular AA's. It's a good budget radio capable of good, loud sound and capable of DX on the MW/AM band.

AN EXPERIMENT IN SONY FENCE DX'ING
My Sony ICF-38 being boosted by a 100 foot cyclone steel fence. It boosted signals on several channels by around 2-3 db. The antenna is underneath the tuning dial.

Late this summer while I was outside a lot working into the night, clipping back a large patch of Himalayan blackberries I realised that my cyclone fence might just act as a signal booster. I grabbed my trusty Sony ICF-38 and brought it out and tested it. Instantly, the fence boosted signals by about 2-3 db on some channels. Here you can see a low signal channel in the mid part of the band pushing the red signal LED on the radio on a medium DX night. The section of fence is nearly 100 feet (30 meters) long.

If you happen to have a steel fence nearby, don't neglect to try using it as an outdoor signal booster.

SUMMER IN SEPTEMBER -- A FEW PICTURES
As I finish this blog post, it is below freezing outside, and Christmas is only two and a half weeks away. It seems this year just flew by. We had a decent summer here in Seattle -- it was 81 degrees F as late as the last week of September. here are a couple pictures from September 27th, when it hit 86 in the afternoon:
I did some major cutting back of a hedge during beautiful, sparkling California-like weather in late September this year. It was awesome working in the sun.
A lone apple in my apple tree in late September. I still have no idea what type of apple this is.
Eddie the Grasshopper hung out inside the house for about a month this summer. I have no idea where he went -- within a week and a half or so after taking this picture of him, he disappeared.        :-(
On some occasions during the summer we have great sunrises -- usually the good sunrises are during the colder months.
I managed to set up my amp and guitars in a better room and had a chance to play them for the first time in a couple months starting in September.
Here you can see the thermometer reads just over 86 degrees F, during the last week of September, 2017. Summer in September -- not common here in Seattle. The blue liquid is a workout drink.

Now we are finally hitting Winter. I close this post with a couple pictures from last year: outdoor Christmas ornaments.
Right now, it is frosty outside.... Not unlike the way the ground looks in the bottom picture.

Hope all of you are having a great December this year.

CC 9-2017 and 12-7-2017

ADDENDUM, August 25th, 2023:
For the last 3-4 years my PR-D6 has been laid up. It's my fault, I inadvertently left it in my car overnight, probably in Summer of 2018, and it ended up roasting on the seat or dash during the next day, which was probably a hot July or August day. Suddenly, the radio wouldn't tune well. The tuning needle was bent from the heat. What had happened was one of the little plastic 'pins', that hold the dial string in place, bent from the head, making the string slacken, and the tuner knob worthless. I still am at a loss as to how to fix it without wrecking the dial string. So I keep putting it off.

Meanwhile, a reader has mentioned that he got a PR-D6 earlier this year, and that his PR-D6 is stereo on FM through the headphones. This is after I answered a question in the comments below, where an earlier reader asked me if the PR-D6 is stereo.

I had checked FM on my radio, by taking the front off and turning the big plastic tuning wheel, and tuning to several, strong FM music stations and noted it was all in MONO.

After the second reader mentioned -- just this week -- that his or her PR-D6 was stereo through the headphones, I took a second look at the chips used by this radio, and yes, the chips themselves are indeed stereo capable. But I just did another test of my PR-D6 and my PR-D6 is still in MONO on local music FM stations.

Sangean must have reconfigured the headset wiring to make the PR-D6 stereo on FM after I got my radio in August or September of 2016. 

So, apparently now the PR-D6's are in stereo on FM through headphones, which is a good feature.

I still have to figure out a way to fix my PR-D6. Maybe I'll cut a hole in the front, attach some sort of mechanism to the wheel and tune it that way. Right now it's easier to just put it off. :-)

Don't leave your PR-D6's out in the heat, guys. They don't like sitting for long periods in hot cars in the summer.

If I fix my PR-D6, I'll post an article on it. I'll have to. :-)