Date   

New Parts for FSL and Air Core PVC Loop Antennas

Todd
 

Hi Gary, and All.

Recently an Australian DXer constructed a 135 mm diameter MW FSL using forty one Jaycar LF1010 (9 x 100 mm) ferrite rods. These rods are more affordable than anything else available on Australian eBay [1].

Jaycar Electronics Australia also sell a larger (9 x 180 mm) ferrite rod [2].

In terms of optimal FSL signal gain and Q, what is the preferable ferrite rod size to use among the two Jaycar available options? Also, how are the number of Litz wire turns calculated to provide 520 to 1750 KHz coverage for a given number of rods? A new article would be instructive factoring in the more recently available rod dimensions, and improved lower resistance Litz wire.

When I built your 40" PVC tabletop box loop design using 9 turns of wire, I fortunately chose the higher Q 8:1 reduction drive variable capacitor from Mike's Electronic Parts [3].

Any thoughts on the theory behind why certain variable capacitors offer higher Q?

Regards,

Todd

1. https://www.jaycar.com.au/9mm-x-100mm-inanimate-ferrite-rod/p/LF1010

2. https://www.jaycar.com.au/180mm-x-9mm-ferrite-rod/p/LF1012

3. https://www.mikeselectronicparts.com/product/384pf-air-variable-capacitor-with-81-planetary-reduction-drive/


Re: Tecsun PL-310 vs PL-380

dwight richardson
 

Thanks Gary.  Excellent information. For domestic MW fans like myself, the Traveler III is looking good. 
--
Bob Richardson


My Ultralight Radios for Sale

Paul Blundell
 

https://www.ebay.com.au/itm/293583454547

Please email me directly: tanger32au@...
--
Paul - Moderator
UltralightDX


Re: Tecsun PL-310 vs PL-380

dwight richardson
 

Thanks Gary. I happened across your excellent discussion of ultralights a few weeks back. Reading again just now, I might have to rethink the Tecsun only agenda. Or have some fun finding an original 310 (non-et) on eBay and compare against the Skywave. Or just try them all. Runner ups might make nice gifts for my cronies. But the Traveller III might need more consideration. At any rate, I am reminded of the folly of trying to pick “the best” of anything. After all - beauty is in the eye. Thanks again. This group is great. I imagine myself as a rookie kid who has happened On to a good bunch of radio guys to learn from. At 66 I’m good with that. I might have something to offer one day. But for now I’m a sponge. 
--
Bob Richardson


Re: PL-606 sticky buns ...

Peter Laws
 

On Mon, May 18, 2020 at 8:07 AM Ron Layton via groups.io
<micron327@...> wrote:

It seems I have made a great error. It was not my PL-600 but my venerable RS DX-440 which has the rubbery push buttons.that developed the gummy decomposition. I
Lol! No "great errors" in hobby radio unless you are operating a transmitter.

I did exercise the buttons on my '606 and they seem better (20 or so
pushes apiece). I do note that, despite the exercise, some buttons
feel different. I suppose more exercise will help that. Alas, it's
morning work Zoom so that will have to wait.



--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!


Re: Tecsun PL-310 vs PL-380

Richard Allen <dx747j@...>
 


From: "Richard N. Allen" <dx747j@...>
Date: May 18, 2020 at 08:50:44 CDT
To: "Gary DeBock via groups.io" <D1028Gary@...>
Subject: Re: [UltralightDX] Tecsun PL-310 vs PL-380

I still occasionally use my PL-310 and PL-380.  Both are of the originally incarnation of the receivers.  When new the PL-310 was unbeatable for receiving Asian stations barefoot.  It offered selectivity not seen in earlier handheld receivers, and had a slight edge over the PL-380 in receiving weak signals.  However, when used in conjunction with a FSL antenna the PL-380 shined.  The evidence is my reception of station 3LO at 14592 km (9067 miles) on a PL-380 with an 8-inch FSL in 2016.  

But, because the controls on the Tecsun receivers became trickier to use over time I turned to using a Skywave receiver.  It is every bit as good as the Tecsuns with fewer of their problems.   It works well when coupled to a FSL or Wellbrook ALA1530LNP antenna.  Last winter I was able to add three new Japanese stations to my log and again hear 2BL on the Skywave.  Overall, it’s the best URL presently available.

Good DX all.

Richard Allen,
near Perry OK USA

_,_._,_


Re: PL-606 sticky buns ...

Steve Nichols
 

I had a pair of binoculars that went the same way. I rubbed the sticky plastic with Armoural, a car interior treatment, and that did the trick.

Steve


Re: Tecsun PL-310 vs PL-380

dwight richardson
 

Thanks for the input. I like the antenna jack on the PL-310. But a simple induction loop would do the same. Non recessed tuning knob sounds good too. 
--
Bob Richardson


Re: Tecsun PL-310 vs PL-380

jcfontario
 

Thanks Gary, that's good to know for the future (not that I am planning to do any travelling for a while, due to COVID).

j


On 05/18/20, "Gary DeBock via groups.io" <D1028Gary@...> wrote:
On Sun, May 17, 2020 at 03:09 PM, jcfontario wrote:
I have a CC Skywave portable radio, but I am not familiar with what a "supercharged" Skywave receiver has that I don't have. What do I need to add to my travel portable?
Hi John,

A "supercharged" Skywave refers to a model with a 7.5 inch transplanted loopstick. This modification greatly increases MW band sensitivity compared to the stock CC Skywave, transforming the radio into something like a dream travel portable.

Unfortunately, the technical procedure for creating this "dream travel portable" is somewhat of a nightmare. The Skywave portable is extremely compact, and crammed with components which fit together like a twisted puzzle. In addition, the RF circuit board connections for the loopstick Litz wire leads are in the worst possible place for this type of modification, making the entire procedure a very demanding test of close-order soldering, sharp eyesight and steady nerves. For this reason the modification procedure has never been written up in article form, although about 5 of these models have been constructed and given to friends in the US, Japan and Australia.

Gary DeBock (in Puyallup, WA, USA)  


Re: PL-606 sticky buns ...

Ron Layton
 

It seems I have made a great error. It was not my PL-600 but my venerable RS DX-440 which has the rubbery push buttons.that developed the gummy decomposition. I don't know if there is a membrane under the keyboard on the 660 but I have had my 600 apart and didn't see any membrane. The 600 has the same plastic keys as the 660. I believe there is a tiny amount of rubber membrane around the tiny push buttons themselves if its like most other radios and this could be the culprit. Perhaps it protects the internals of the buttons from dust? Who knows.....I think my DX-440 developed this because I kept it in a closet, unused, for many years and it got hot. All the old Sangean produced radios had a full rubber pad with the external push buttons in one piece. When these go bad it can be a real chore to clean them up. I passed on buying a mint ATS-803a because of this problem.


Re: Tecsun PL-310 vs PL-380

Gary DeBock
 

On Sun, May 17, 2020 at 03:09 PM, jcfontario wrote:
I have a CC Skywave portable radio, but I am not familiar with what a "supercharged" Skywave receiver has that I don't have. What do I need to add to my travel portable?
Hi John,

A "supercharged" Skywave refers to a model with a 7.5 inch transplanted loopstick. This modification greatly increases MW band sensitivity compared to the stock CC Skywave, transforming the radio into something like a dream travel portable.

Unfortunately, the technical procedure for creating this "dream travel portable" is somewhat of a nightmare. The Skywave portable is extremely compact, and crammed with components which fit together like a twisted puzzle. In addition, the RF circuit board connections for the loopstick Litz wire leads are in the worst possible place for this type of modification, making the entire procedure a very demanding test of close-order soldering, sharp eyesight and steady nerves. For this reason the modification procedure has never been written up in article form, although about 5 of these models have been constructed and given to friends in the US, Japan and Australia.

Gary DeBock (in Puyallup, WA, USA)  
 


Re: Tecsun PL-310 vs PL-380

jcfontario
 

Hi Gary,

I have a CC Skywave portable radio, but I am not familiar with what a "supercharged" Skywave receiver has that I don't have. What do I need to add to my travel portable?

Thanks

John Fisher


On 05/17/20, "Gary DeBock via groups.io" <D1028Gary@...> wrote:
Hello All,

When both the original PL-310 and PL-380 were introduced by Tecsun in 2009-2010 they were fully reviewed (at http://www.mediafire.com/file/w4yuzhj2kyz/Tecsun_PL-380_Review.pdf/file   for the PL-380, and http://www.mediafire.com/file/q8pbn34i1nangl4/The_Tecsun_PL-310.pdf/file  for the PL-310. Unfortunately, since that time Tecsun has followed the tendency of many Chinese companies to cut the quality of their products in order to increase profits, resulting in new digital quirks (and other issues) in these models.

In 2012 Tecsun removed the shielding around the Si4734 DSP chips in their PL-380 models (and probably in their PL-310's and PL-606 models as well), resulting in a digital whine whenever the display is grasped by the hand. The PL-310 was stripped down into a completely different model to make the lower quality PL-310ET, as described in the 2015 Ultralight Radio Shootout (posted at https://swling.com/blog/2015/03/gary-debocks-2015-ultralight-radio-shootout-review/
In my opinion neither the newer PL-380's nor the PL-310ET are really suitable for important overseas DXpeditions, which are much more demanding because of the rough environments, temperature extremes and travel bumps. The newer C.Crane Skywave and Skywave SSB models lack some of the digital search features of the Tecsun models but have much higher quality overall, including a new DSP chip which outperforms the Tecsun Ultralights in the most important categories (MW sensitivity, freedom from internally generated heterodynes and superior 1 kHz DSP audio). Whenever a friend goes with me on an important overseas DXpedition I always provide them with a "supercharged" CC Skywave model, which is fully capable of tracking down great DX all by itself (such as 1000-Radio Record in the Cook Islands, 1431-Djibouti in Hong Kong, etc.). Unfortunately the CC Skywave models do cost significantly more than the Tecsun Ultralights, but the increased cost is worth it, in my opinion. For someone who cannot afford US $90 for a new Ultralight, the newer PL-380 would be OK if you don't mind the significant digital quirks.

73, Gary DeBock (in Puyallup, WA, USA)
  


Re: Tecsun PL-310 vs PL-380

C B
 

Thus spake our resident Ultralight and FSL experimenter/developer extraordinaire. I can happily attest to Gary’s Ultralight and FSL prowess.

73,

Craig Barnes
Wheat Ridge, CO


On May 17, 2020, at 1:36 PM, Gary DeBock via groups.io <D1028Gary@...> wrote:

Hello All,

When both the original PL-310 and PL-380 were introduced by Tecsun in 2009-2010 they were fully reviewed (at http://www.mediafire.com/file/w4yuzhj2kyz/Tecsun_PL-380_Review.pdf/file   for the PL-380, and http://www.mediafire.com/file/q8pbn34i1nangl4/The_Tecsun_PL-310.pdf/file  for the PL-310. Unfortunately, since that time Tecsun has followed the tendency of many Chinese companies to cut the quality of their products in order to increase profits, resulting in new digital quirks (and other issues) in these models.

In 2012 Tecsun removed the shielding around the Si4734 DSP chips in their PL-380 models (and probably in their PL-310's and PL-606 models as well), resulting in a digital whine whenever the display is grasped by the hand. The PL-310 was stripped down into a completely different model to make the lower quality PL-310ET, as described in the 2015 Ultralight Radio Shootout (posted at https://swling.com/blog/2015/03/gary-debocks-2015-ultralight-radio-shootout-review/
In my opinion neither the newer PL-380's nor the PL-310ET are really suitable for important overseas DXpeditions, which are much more demanding because of the rough environments, temperature extremes and travel bumps. The newer C.Crane Skywave and Skywave SSB models lack some of the digital search features of the Tecsun models but have much higher quality overall, including a new DSP chip which outperforms the Tecsun Ultralights in the most important categories (MW sensitivity, freedom from internally generated heterodynes and superior 1 kHz DSP audio). Whenever a friend goes with me on an important overseas DXpedition I always provide them with a "supercharged" CC Skywave model, which is fully capable of tracking down great DX all by itself (such as 1000-Radio Record in the Cook Islands, 1431-Djibouti in Hong Kong, etc.). Unfortunately the CC Skywave models do cost significantly more than the Tecsun Ultralights, but the increased cost is worth it, in my opinion. For someone who cannot afford US $90 for a new Ultralight, the newer PL-380 would be OK if you don't mind the significant digital quirks.

73, Gary DeBock (in Puyallup, WA, USA)
  


Re: Tecsun PL-310 vs PL-380

Gary DeBock
 

Hello All,

When both the original PL-310 and PL-380 were introduced by Tecsun in 2009-2010 they were fully reviewed (at http://www.mediafire.com/file/w4yuzhj2kyz/Tecsun_PL-380_Review.pdf/file   for the PL-380, and http://www.mediafire.com/file/q8pbn34i1nangl4/The_Tecsun_PL-310.pdf/file  for the PL-310. Unfortunately, since that time Tecsun has followed the tendency of many Chinese companies to cut the quality of their products in order to increase profits, resulting in new digital quirks (and other issues) in these models.

In 2012 Tecsun removed the shielding around the Si4734 DSP chips in their PL-380 models (and probably in their PL-310's and PL-606 models as well), resulting in a digital whine whenever the display is grasped by the hand. The PL-310 was stripped down into a completely different model to make the lower quality PL-310ET, as described in the 2015 Ultralight Radio Shootout (posted at https://swling.com/blog/2015/03/gary-debocks-2015-ultralight-radio-shootout-review/
In my opinion neither the newer PL-380's nor the PL-310ET are really suitable for important overseas DXpeditions, which are much more demanding because of the rough environments, temperature extremes and travel bumps. The newer C.Crane Skywave and Skywave SSB models lack some of the digital search features of the Tecsun models but have much higher quality overall, including a new DSP chip which outperforms the Tecsun Ultralights in the most important categories (MW sensitivity, freedom from internally generated heterodynes and superior 1 kHz DSP audio). Whenever a friend goes with me on an important overseas DXpedition I always provide them with a "supercharged" CC Skywave model, which is fully capable of tracking down great DX all by itself (such as 1000-Radio Record in the Cook Islands, 1431-Djibouti in Hong Kong, etc.). Unfortunately the CC Skywave models do cost significantly more than the Tecsun Ultralights, but the increased cost is worth it, in my opinion. For someone who cannot afford US $90 for a new Ultralight, the newer PL-380 would be OK if you don't mind the significant digital quirks.

73, Gary DeBock (in Puyallup, WA, USA)
  


Re: PL-606 sticky buns ...

Peter Laws
 

On Sun, May 17, 2020 at 10:37 AM Ron Layton via groups.io
<micron327@...> wrote:

My PL-600 developed a bad case of gummybearitis and the cure is hi proof isopropyl alcohol as given above. I'm fortunate to own a few gallons of 99.9% so cutting it down with the appropriate amount of distilled water saved the day. I think I ended up with about 91% or so. I wish I knew what causes the breakdown as I've experienced this with another radio and an electronic scale. Good luck with your repair.

I wasn't clear in my description. At all. It isn't that my fingers
stick to the keys (no rubber on the exterior, thankfully, metalized
plastic) it's that the keys themselves seems to not push well or
release well. I often have to really push to make the switch do its
thing. Is this a membrane underneath? I suppose I should take it
apart and see. :/



--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!


Re: Tecsun PL-310 vs PL-380

Gord Seifert
 


    I do love the preset tuning on the 310et! Press a button to get into VM mode and tune through them with the tuning knob. So much quicker and more intuitive than the banks (Pages) of seven presets each on the Eton Satellit Grundig Edition that need to be accessed individually using the Up and Down arrow keys to access the desired bank (after pressing the Page/Time button) and then one of seven function keys to chose the station within that bank. It does allow saving tons of stations, organized by band, or type of music, or whatever you choose. Still, I like the 310et's presets much more, for the simplicity and speed.

    But, I really dislike the 310et tuning in that it tunes VERY slowly (1 khz per notch) by default. When I want to tune at a more reasonable speed I have to spin the tuning knob way to fast to get it into fast tuning mode. Then it suddenly jumps into fast mode (5 khz per notch on SW and 10 on MW) and, since I am spinning the knob so quickly to get it into fast mode, it winds up far beyond where I wanted to be. Then, once I have it in the more reasonable fast mode, it falls back to slow mode far too quickly. The default should be 5 khz on SW and 10 khz on MW since that is the normal station spacing. Slow tuning should be an option under control of a switch. On the Eton the tuning speed is chosen by pressing the tuning knob in against a switch. Perfect!

    No complaints with reception with my 310et, other than an overactive AVC, but the tone is pretty poor.
     


Re: PL-606 sticky buns ...

Ron Layton
 

My PL-600 developed a bad case of gummybearitis and the cure is hi proof isopropyl alcohol as given above. I'm fortunate to own a few gallons of 99.9% so cutting it down with the appropriate amount of distilled water saved the day. I think I ended up with about 91% or so. I wish I knew what causes the breakdown as I've experienced this with another radio and an electronic scale. Good luck with your repair.


Re: Tecsun PL-310 vs PL-380

James Fields <james.v.fields@...>
 

I love the "Tecsun way" of tuning - I love the ETM feature on the smaller models, which basically works like "Page 0" on the bigger ones.  Love that you can switch between dedicated VF/VM modes so you don't have to push a frequency button every time you enter a frequency.  I was really excited back when I got my 310ET to find that it had all that and for about $40.  Unfortunately it just isn't a great performer.  It's suitable for picking up strong locals so it's ok to take out to the driveway when I wash the car but I never use it for SWL or for nighttime MW DX.

I do so wish I could get a tiny radio with the Tecsun tuning and memory schemes combined with the performance of a Skywave SSB.  It's dreams like that which keep guys like me racking up a closet full of radios.

On Sat, May 16, 2020 at 7:17 PM DXer <hfdxmonitor@...> wrote:

I own three of the cheaper Tecsun DSP models – PL-310ET, PL-380 and PL-606.
I had the PL-606 for a while, good radio BUT, unless you are a fix frequency listener, changing frequency 'gets old' quickly.

I gave it to my mother. She has been tuning to the same station for 50+ years. Actually, it changed recently, when the station moved from AM to FM. I then gave her a Sangean PR-D5.  :^)

My memory is not what it used to be, but wasn't the PL310ET the 'victim' of some 'improvements' that negatively impacted its performance?

I still have the PL-390, but I'm not sure it meets the Ultralight standards. If it does, it's a very nice radio as well.

Regards,

Vince
Ottawa, ON



--
James V. Fields
james.v.fields@...


Re: Tecsun PL-310 vs PL-380

Rémy Friess
 

As far as I know soft-mute can be de-activated on both receivers.

I find the recessed tuning-knob to be advantage rather. If you travel a lot and take your pl-310 in an out of your suitcase or move it around a lot the tuning-knob can easily fall off. I lost mine twice. This cannot happen with the PL-380.

Le 17/05/2020 à 14:01, h. garcia a écrit :

Here's what I recall, but please, double check it... This is top of my head:

PL-310

Goods: antenna jack; real, external tuning knob (you can use two fingers)

Not so good: noticeable soft-mute, in severe fading you need to detune by 1KHz to avoid the audio 'pumping' effect.


PL-380

Good: very little or no soft-mute

Not-so-good: no antenna jack; tuning knob is recessed, you can only use one finger, akin to the volume knob we're used to see with UL receivers.



On Sun, May 17, 2020, 07:15 Rémy Friess <rfriess@...> wrote:

Le 17/05/2020 à 03:16, DXer a écrit :
>
> Both the volume and tuning encoders became 'independent' of me very
> early on. I want to increase the volume, it decreases it and vice-versa.
>
> The tuning encoder is the same, but also decides the tuning speed


Re: Tecsun PL-310 vs PL-380

h. garcia
 

Here's what I recall, but please, double check it... This is top of my head:

PL-310

Goods: antenna jack; real, external tuning knob (you can use two fingers)

Not so good: noticeable soft-mute, in severe fading you need to detune by 1KHz to avoid the audio 'pumping' effect.


PL-380

Good: very little or no soft-mute

Not-so-good: no antenna jack; tuning knob is recessed, you can only use one finger, akin to the volume knob we're used to see with UL receivers.



On Sun, May 17, 2020, 07:15 Rémy Friess <rfriess@...> wrote:

Le 17/05/2020 à 03:16, DXer a écrit :
>
> Both the volume and tuning encoders became 'independent' of me very
> early on. I want to increase the volume, it decreases it and vice-versa.
>
> The tuning encoder is the same, but also decides the tuning speed
> rate. I want to go slow, it goes faster and vice-versa._._,_._,_

I had a similar problem with the tuning knob of my Tecsun PL-660 once.
It seems this happens if the set (or the knob) has not been used for a
while.

I turned the knob for about 15 minutes at high speed in both directions
with power on and then it worked again.

I don't know if this will work with your 310ET, but you might want to try.

And yes the ET is not as good as the original 310. I replaced the 310
with the 310ET only to find that it was much less sensitive and the
audio was ghastly.

I then bought a PL-380 and I'm very pleased with it.

73, Rémy.





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