Tag Archives: Modifications

Tecsun PL-680: Rolf touts enhanced performance using PL-660 mod

Many thanks to SWLing Post contributor, Rolf Snijder, who writes:

I have made the same modification to the Tecsun PL-680, that was done [by many on the] PL-660 earlier.

The PL-680 is now a great radio; I think now one of the best! I do not own a PL-660, so I cannot compare.

Photo detail

Overview of modification.

For disable soft mute you can see the 2 joints and you must scratch a path on the print near the switch. (same on a PL-660)

Closeup of joint #1 (click to enlarge)

Closeup of joint #2 (click to enlarge)

With the tone switch [on the left side panel of radio] you can turn the muting on and off. On FM I need to set it on for better results, but on LW MW and SW always off!

Frequency adjust is with the pot: adj1391 in the right corner. (for the 1 kHz off freq)

Click to enlarge.

Hope I can help someone with this on your great site.

Greetings,

Rolf Snijder
Netherlands

Many thanks for sharing this PL-680 mod, Rolf! This seems like a simple enough project and one that can be undone if you aren’t pleased with the results.

Post readers: Please comment if you’ve made this modification to your PL-680 or PL-660 or if you have other successful modifications to share!

How to fix the Grundig S350DL’s mechanical tuning drift problem

5 Replies

The S350DL may look like a digital radio, but it’s actually analog inside and tuning is prone to drift.

Many thanks to SWLing Post contributor, Ed, who noted my comments about the Grundig S350DL’s tuning drift yesterday, and shared the following fix found on Jeff McMahon’s Herculodge blog.

Ed writes:

The Grundig S350DL’s mechanical tuning drift problem is reportedly easily correctable with a screwdriver:

(Source: The Herculodge)

[…]The drift on AM was terrible! After 10 minutes, it is jumping all over the place – if you touch the radio, the sound mutes and the display goes nuts. I pack it up to take it back but then I decide to google the problem and find this:

http://groups.yahoo.com/group/Grundig-S350/message/4644

I do exactly what he says – I pull off the cover after unscrewing all of the screws (including the 2 in the battery compartment).

Only the speaker is attached to the front. I remove the three screws from the display and then tighten the two screws on the tuning wheels. They were barely loose – almost not noticeable – so I was not too optimistic. I carefully got it all back together (the plastic pieces that hold the fabric handle on only go back on one certain way and were sort of a pain!). I cross my fingers, plug it in, and wow – a brand new radio. The tuning is perfect. Zero drift on FM and AM. AM sounds excellent.[…]

I have an earlier Grundig S350 that I bought at a hamfest years ago which had an easily-fixed power problem. For $20 it makes a nice bathroom radio and it sounds great, especially on FM.

BTW, I found schematics for it on radiomuseum.org, which is a great resource for radio schematics.

Thanks for the tip, Ed! I think I’ll crack open my S350DL later today and give this a try!

Simple modification to disable soft mute on the Tecsun PL-210

2 Replies

Many thanks to SWLing reader, Mini, who wites:

I am Japanese short wave listener.

I found the method that disable soft-mute of TECSUN PL-210.
And, I posted the article in my blog.

Please forgive me that may be difficult for you to understand the content.
It is automatic translation from Japanese my blog.

Thanks mini

Click here to read Mini’s blog post via Google translate.

Click here for the original in Japanese.

Thank you, Mini! I don’t have the PL-210, but if I did I would certainly disable the soft mute as I find it very distracting during routine band scans.