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Old 30th Apr 2016, 7:59 pm   #1
Edward Huggins
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Default Grundig "Yacht Boy"

My wife bought me this as a Birthday present in March 1973. Wot a trouper! It still works perfectly and sounds superb. The pull-out bass cut feature is really neccessary on speech based progammes and even on certain kinds of music. With it in, the bass is just sensational. Just what was it that made these sound so good, was it the double-wound IFTs, the high RF gain or the soft suspension 7" x 5" speaker - or what? Certainly as good, or better, as any Hacker or Roberts of that period and maybe any current Roberts model.....That pedigree still continues in the name of ETON today. Edward
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Old 30th Apr 2016, 8:09 pm   #2
stevehertz
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Default Re: Grundig "Yacht Boy"

Grundigs are great. My favourite.
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Old 30th Apr 2016, 9:14 pm   #3
mhennessy
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Default Re: Grundig "Yacht Boy"

Short answer: a wildly excessive amount of bass boost caused by the dual loudness taps.

Longer answer can be found here: https://www.vintage-radio.net/forum/...4&postcount=10

My N210 is in this room, next to a Hacker Hunter. I agree that the Grundig has excellent sensitivity, especially on FM. But it's the Hunter that gets used daily.
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Old 30th Apr 2016, 9:15 pm   #4
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Default Re: Grundig "Yacht Boy"

The speaker and generous microfarads in the audio stages plus slow agc give the bass.

Double-tuned IFTs give a wider, M-shaped passband without worsening adjacent-channel rejection and keep the audio flatter out into the treble region.

There was an old joke which said Grundig designed a really good set, then saw how many parts could be removed before it stopped working

David
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Old 30th Apr 2016, 9:16 pm   #5
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Default Re: Grundig "Yacht Boy"

Presumably this is a 209 or 210. These are great radios in all respects. The tone control gives a bass boost if you push it in, not a cut if you pull it out.
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Old 30th Apr 2016, 9:24 pm   #6
mhennessy
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Default Re: Grundig "Yacht Boy"

See the schematics in the link I posted previously. Pulling out the bass control puts a 10n cap (C612) in series with the audio path, so it effects a bass cut. The bass boost (approx 25db of it!) is provided by C616 and C617 around the volume control.
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Old 1st May 2016, 12:40 am   #7
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Default Re: Grundig "Yacht Boy"

Yes, I know this is literally true, but the tone control 'out' position gives a subjectively neutral frequency response. This is almost certainly how Grundig intended the radio to be used. I am well aware of the frequency shaping around the volume control - this radio doesn't have pretensions to offer high fidelity reproduction, rather it has the classic 50s/60s 'nice tone'.
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Old 1st May 2016, 10:29 am   #8
GeoffK
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Default Re: Grundig "Yacht Boy"

The bass cut switch also places R611 across the tone control and virtually in parallel with the volume control. Grundig should have given the option of switching out the loudness components, which are nothing to do with the tone control circuit.
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Old 1st May 2016, 10:50 am   #9
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Default Re: Grundig "Yacht Boy"

The Yacht Boy was the European answer to the Zenith Trans-Oceanic that I drooled over on the back covers of Grandad's National Geographics.

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Old 1st May 2016, 11:00 am   #10
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Default Re: Grundig "Yacht Boy"

Ah....The Trans Oceanic, an evocative name, which captures one's imagination.

Lawrence.
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Old 1st May 2016, 11:21 am   #11
stevehertz
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Default Re: Grundig "Yacht Boy"

Quote:
Originally Posted by Radio Wrangler View Post
The Yacht Boy was the European answer to the Zenith Trans-Oceanic
I'd say that Grundig's Satellit series were their answer to Zenith's Trans-Oceanics. The Satellit series being aimed at the more serious, 'all world' DXer/enthusiast while the Yacht Boy was aimed at those simply wanting a very good quality, versatile, portable radio.

Yacht boy: http://myweb.tiscali.co.uk/grundigradioboy/yb210.htm
Satellits: http://www.classic-worldband.com/
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Old 1st May 2016, 12:36 pm   #12
mhennessy
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Default Re: Grundig "Yacht Boy"

Quote:
Originally Posted by paulsherwin View Post
Yes, I know this is literally true, but the tone control 'out' position gives a subjectively neutral frequency response. This is almost certainly how Grundig intended the radio to be used.
Yes, I remember considering this as a possibility when I did my initial analysis some 5/6 years back. However, for 2 reasons I concluded that wasn't the case:

1. Why didn't they simply reverse the connections to the SPDT switch, so the tone knob isn't sticking out by 1/4 inch by default?

2. With the tone control pushed in, it sounds like pretty much every other Grundig set I've heard

Additionally, I've subsequently obtained a photocopy of the user manual. It says this:

Quote:
In addition the bass response can be reduced by pulling the tone control knob forwards.
After Hacker and Roberts, Grundig are the next largest part of my collection - I've got a lot of them, and have serviced many more for others (not always a pleasurable experience!). All their sets, irrespective of size, have a lot of bass (and treble) boost built into the loudness tapping(s), and actually, I give them points for that - they had a "house sound", and they knew how to get it. They weren't alone, of course - the Roberts R707 being an obvious example. Even Fidelity did it (e.g. RAD 15 and RAD 21). Heck - I've done it! However, they sometimes went over the top with it, and the N210 is an example of that. I'm sure they got away with it at the time - but with modern bass-heavy programme material and Optimods, the bass lift is too much for the amplifier and plastic cabinet to handle.
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Old 1st May 2016, 12:40 pm   #13
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Default Re: Grundig "Yacht Boy"

Well, that's fair enough. The tone control and frequency shaping arrangements are certainly odd in this set.
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Old 1st May 2016, 1:01 pm   #14
mhennessy
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Default Re: Grundig "Yacht Boy"

Quote:
Originally Posted by Hetrodyne View Post
The bass cut switch also places R611 across the tone control and virtually in parallel with the volume control. Grundig should have given the option of switching out the loudness components, which are nothing to do with the tone control circuit.
I suspect that R611, which ends up being in parallel with the 100k volume pot track, is just there to give the right impedance "seen" by C612 so the turnover frequency is what they intended. Perhaps it also smooths out the variations caused by the bass boost circuits (the 100k won't really be 100k at low frequencies). When I ran the sims, I don't remember it making much difference - the files are on a computer at work, so I can revisit them when I get a quiet moment.

The dual-tap approach is surprisingly common on Grundigs - though most use the same approach as a single loudness tap, where the tone control shorts out the bass-lift capacitor when turned to the "high" end.
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Old 1st May 2016, 2:10 pm   #15
Edward Huggins
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Default Re: Grundig "Yacht Boy"

Many thanks for all of your Posts. This has given me an insight into the tone control's design parameters and I have revised my views to to it being a "Bass Cut" device. I now realise that the function is that of a "Bass Boost". This accounts for the excellent, well balanced, sound in the non-boost setting. That dual tap on the potentiometer must be a near unique feature. I also agree it would have been a more elegant solution to have had the default setting when the knob was pushed in. Edward
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