Pre-Detection Recordings: Any in existence, declassified and accessible–?

Many thanks to SWLing Post contributor, Chip, who writes:

I remember reading a number of years ago that the NRO/NSA was the largest consumer of magnetic tape, utilized for pre-detection recordings of various spans of spectrum, all over the world.

I’m wondering if those tapes become declassified at some point, and if they are available through FOIA requests. Were they just bulk erased, destroyed or sold at GSA auction along the way.

Do you know if anyone has ever queried into their existence, and if they have been electronically preserved to some other digital medium?

The idea that our government records huge chunks of spectrum, fuels thoughts in my mind of huge spans of non-classified spectrum from across the years. All the DX shortwave outlets captured for posterity.

Thank you for sharing this note, Chip.

Of course, I’ve always been interested in adding recordings like this to the Radio Spectrum Archive. If these recordings exist, I would love to see them added to the Internet Archive–who stores Radio Spectrum Archive recordings– so that they could be shared and enjoyed by all.

Post readers: If you have any information on this, please comment!

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KFOG broadcasts on June 20th and 26th, 2021 via Channel 292

Many thanks to SWLing Post contributor, Pete Madtone, who shares the following:


KFOG takes to the high seas via Channel 292 on Sunday June 20th 2021 at 1200 UTC (11am UK time) and on Saturday June 26th at 0900 utc (8am UK time) on 6070 kHz. Expect tunes in a nautical style and “see the glimmer from a distant lighthouse, as the buoys ding and the (radio) waves crash onto the rocky shore. This is music from the mist!” as they say at KFOG HQ.

Expect a mix from One Deck Pete called “A mix from across the Pond” with tunes from Kiyoko, Honeychild & DJ Olive, BOATS, Robert Mellin and The Congo’s. Grab yourself a lifejacket and a shortwave radio and tune in. If the shortwave radio is a problem tune in here at the alloted time. If you haven’t a lifejacket we’re sorry but we can’t help you with that!

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A Super-Charged Solar Cycle 25?!

There’s an interesting post from spaceweather.com about two scientists who believe they have found evidence of solar activity which might indicate a super-cycle rivaling the best solar cycles ever recorded. (I, for one, would be thrilled for this since the last such super-cycle seems to have been before I was born, and that was a real long time ago!)

Here’s the link to the article at spaceweather.com:

The Termination Event

73,Robert

Robert Gulley, K4PKM (formerly AK3Q), is the author of this post and a regular contributor to the SWLing Post. 

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Dan reviews latest firmware version of the Tecsun PL-368 and shares list of hidden features

Many thanks to SWLing Post contributor, Dan Robinson, who shares the following guest post:


Revisiting the Tecsun PL-368:  Assessing a Later Firmware Unit

by Dan Robinson

This past April, I reviewed Tecsun’s PL-368, the update of the PL-365 (also sold by CountyComm as the GP5).  There were some major changes:  Tecsun shifted from AA batteries to a flat BL-5C cellphone type battery, and of course the marquee design change was the addition of a keypad.

The keypad is a night and day change – whereas before the PL-365 was a handy receiver but hobbled by archaic tuning limited to memory access and the side thumb wheel, the 368 provides easy instant frequency selection.

In my previous review, I mentioned the well-known characteristic of the 360 and 365 models which exhibited over-sensitivity to the touch.  When removing your hand, signal levels plummeted – usually, a full grip was necessary and any variation caused reduced sensitivity – noticed mostly in shortwave mode.

The PL-368 I reviewed was from among the first versions of the receiver.  It had a firmware of 3681, from a 2020 production run.  Recently, I received from Anon-Co – the most reliable supplier of Tecsun receivers – an updated unit, with firmware 3684.

Please see my previous review for comments on various aspects of the 368: the longer but less robust telescopic antenna, addition of detents on the volume wheel, and the welcome addition of adjustable bandwidths, synchronous detection, and ability to tune in 10 hz increments, and other changes.

PROBLEMS

SYNCHRONOUS DETECTION:  As with the 909x and H-501, the upgraded 368 now has Synchronous Detection.  I did not expect any change in the 3684 firmware – SYNC still has some distortion and loss of lock.

As with the 330, 990x, and 501x successful use of this mode requires a delicate dance involving careful selection of various bandwidths while in SYNC mode and fine tuning.

However, whereas on the previous 3681 unit there was significant “warbling” when in SSB and SYNC, and phonics when touching the keypad, the 3684 unit has little to no such warbling and the phonics appear to be gone, or minimized.

It’s not known what Tecsun may have done to address these issues – my review of a previous 3681 firmware unit was published in April, so it’s hard to think that Tecsun made any major physical changes to the PCB/keypad and radio body.  But there does seem to be some improvement.

I had no expectation that a firmware change would result in any improvement in the other major issue common to the 360 series – reduction of sensitivity when the receiver is not being held in the hand.

The 368 still shows a noticeable reduction in signal strength, visible on the display, when left standing on its own versus being fully gripped.  But the problem does not seem to be as serious as it was with the PL-360/365.

And since my first review of the 368, I have done some additional comparisons with older portables which were constructed with more robust cabinets.  Some of those also exhibited reduced sensitivity when not being held.

For the PL-368 with firmware 3684, the headline really has to be the apparent disappearance of the “phonics” when tapping the keypad and cabinet top surface.  This was the elephant in the room on the first very early sample of the PL-368.

While there is still distortion using SYNC mode, this issue seems to have been slightly reduced with the latest firmware.  Without confirmation by Tecsun, there is no way to know what specifically may have been done to impact the SYNC issue in a positive direction.

A major disappointment is confirmation from Anon-Co via Tecsun that the re-calibration function seen in the PL-330, 990x and H-501x is absent from the PL-368.

That leaves a user with only the fine tuning option in SSB.  This is a real puzzler, since surely Tecsun could have enabled re-calibration on the 368 in the same way it did with the other receivers.

SUMMARY

I stated in my first review of the 368 that this receiver would be an automatic must-buy in my book, were it not for the earlier issues of cabinet phonics and signal level reduction when the radio isn’t being fully gripped in hand.

One hopes that the phonics issue has been fully addressed by Tecsun.  It’s possible that my initial early unit of the 368 had some weakness in the PCB for the keypad, and LCD display that has been recognized and corrected.

Without confirmation from Tecsun, it’s also difficult to declare that the 3684 firmware has truly brought about a measurable improvement in SYNC and SSB.  But based on my testing of this particular 3684 firmware unit, the radio is more usable and tolerable in SYNC and SSB.

And of course, addition of the keypad along with multi-bandwidth options moves the 368 firmly into the same zone as Tecsun’s other portables, albeit perhaps more in the “prepper” category.

There are so many offerings now from Tecsun in portables that it’s hard for me to place the PL-368 in the “must-buy” category, especially since the PL-330, 990x and H-501x bring so many superb features to the game.

But the PL-368 has a certain appeal – its walkie-talkie style design makes it an easy quick-grab for trips, similar to the PL-330, though the 368 can not really be safely balanced on a flat surface and is best used with some kind of stand.

In terms of raw performance, one has to observe that the wonderful Belka DX has to be considered as a top choice and major competition when it comes to extreme portability and top performance, especially with the available speaker/battery backs.

And the PL-368 still has major competition from the XHDATA D-808 (now appearing under the RADIWOW SIHUADON label) with excellent AIR band capability and multiple bandwidths, though no synchronous detection.

To “save” the PL-36xx series, Tecsun will have to ensure steady QC (quality control) in manufacturing and when possible, further firmware updates of the 368, as with all Tecsun receivers.


Preliminary List of Hidden Features for PL-368

Source: Anna at Anon-Co

Switch between internal ferrite rod and whip on AM (MW & LW)

1. Select the MW or LW band.
2. Press and hold key ‘3’ for about 2 seconds.

When the display briefly shows “CH-5” this means that the device is set to MW/LW reception using the telescopic antenna. The display shows MW (or LW) and SW on the left side of the screen.

When the display briefly shows “CH-A” this means that the device is set to MW/LW reception using the internal ferrite antenna. The display shows only MW (or LW) on the left side of the screen.

Adjusting the maximum volume level

Select the frequency band, then press and hold key ‘7’ for 2 seconds until a number is displayed. At this moment, rotate the [ TUNING ] knob to adjust and press the key ‘7’ again to save and exit.

Firmware Version

In power-off mode, press and hold [ VF/VM ] for 0.5 seconds until all characters on the display are shown, then wait a few seconds until the firmware version is briefly displayed at upper right of the display.

Extend SW-range for European setting (1621-29999 kHz)

1. In power-off mode, press and hold the [ 3 ] key to set the MW tuning steps to 9kHz.
2. Select the SW band, and then press and hold the [ 5 ] key for 10 seconds to enable/disable the SW frequency extension.

The starting point of the SW frequency range will become 1621 or 1711 kHz.

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Lithuania: 95th anniversary of first radio transmission

Photo credit: Lietuvos centrinis valstyb?s archyvas.

Many thanks to SWLing Post contributor, Giedrius Blagnys, who notes:

The first national radio broadcast in Lithuania started on 1926-06-12 d. Photo above: the mic used for the first broadcast. 

Recording of the first transmission:

Many thanks for sharing this interesting bit of history with us, Giedrius!

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The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:


The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

by 13dka

When Thomas got wind of its development in 2019 he immediately asked “could the Icom IC-705 be a shortwave listeners holy grail receiver?”. I usually wince a little when I hear “holy grail” because it means very different things to different people, it’s also a moving target with many people aiming at the spot where it was decades ago. But Thomas certainly had a very level-headed assembly of technical performance, quality and practicality requirements in mind when he used that term, and I thought he might be onto something!

There are some excellent, trustworthy reviews of the IC-705 out there. The following is not one of them, I just want to share an opinionated breakdown on why I think this is an interesting radio for SWLs/BCLs indeed, also deliberately ignoring that it’s actually a transceiver.

Jumping shop

While the era of superhet/DSP-supported tabletop holy grails ended with the discontinuation and sell-off of the last survivors more than a decade ago, powerful PC-based SDR black boxes were taking over the mid-range segment and it became very slim pickings for standalone SWL receivers: Thomas just recently summed up the remaining options here.

Between the steady supply of inexpensive yet serviceable Chinese portables, upgraded with a least-cost version of DSP technology, and the remnants of the high end sector there’s very little left to put on the wish list for Santa – that doesn’t need to be paired with a computer that is.

No surprise that SWLs/BCLs in search of new quality toys with tangible controls are taking a squint over the fence to the ham transceiver market: Hams are still being served the best and the latest in radio technology in all shapes and sizes, and even entry-level rigs usually come with feature-rich general coverage receivers. But transceivers never had SWLs much in their focus in the past decades, and particularly not BCLs: Frontend adaptation, additional AM filters, switches and functions would’ve meant increasing costs and so transceivers were never perfected for that purpose. DSP and SDR technology allowed for improvements on that without actually adding (much) hardware and so some interesting alternatives surfaced in the past years, but most of them still come with little downers, at least for BCLs.

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