GRUNDIG CONCERT BOY 1100

I recently took a chance and won this radio at an auction; untested, with a seized tuning mechanism and coated with nictone.

When I got it on the bench, of course, it was totally non-functional. A little probing revealed a shorted filter capacitor in the power supply, which prevented it from working from either AC or batteries. A higher voltage and capacitance-rated part fixed that.


As for the seized tuner, I didn't have a clue what was going on. Thanks to the Internet and Google, I found that this was a common problem on Grundigs of this vintage ('73-'78). Apparently, the grease in the tuning capacitor hardens over time. One suggestion, which worked well for me, was to gently heat the capacitor with a hair dryer until the grease melted, then wash it away with a solvent like lighter fluid. I then re-greased the gears and pivot points with lithium grease, being careful not to get it on the plates. Result.

An unknown knucklehead who owned it before me decided that the headphone jack on the back (which works perfectly well) was not good enough for him. So, he proceeded to drill a hole in the front of the unit, just above the "G" in Grundig, and mount his own jack. The jack's now gone, but the hole remains. As for the nicotine...well, it's gone too, thanks to Windex and paper towels.

Concert Boy Goliath (left) and Partner David (right)

Since I've had my Telefunken Partner 500 for many years and am familiar with its characteristics the most, I will again use it as a benchmark. It seems like an unfair comparison when you look at the relative sizes of these radios...like David versus Goliath. But David puts up a good fight.

Right away, not surprisingly, the difference in bass presence goes to the Grundig. While the Partner's bass response for its size is excellent, physics says the bigger box is going to win. This Grundig big boy comes in at a whopping footprint of 41cm x 22cm x 10cm (approx.) [about 16.25" x 9" x 4"].

The Grundig's communications receiver - style tuning knob 

With telescopic antennas on both radios retracted, it was evident that the FM sensitivity of the Concert Boy was also better than the Partner's. In an urban area, the Partner gets overloaded easily, so lowering the antenna is required to prevent "ghosting" and distortion. The Grundig handled this proliferation of FM signals better, even with its antenna fully extended. Another point for Goliath, but his luck is about to run out.

Switching to the shortwave bands, the Concert Boy was almost useless on its K2 band (SW2 - 6.1 to 18 MHz) because of extreme feedthrough of local FM signals clobbering the weak shortwave signals. While the Partner had no such issue on the 19 m band through to the 41 m band, when a shortwave signal was heard on the Grundig between the FM splatter, the Grundig was slightly more sensitive.

That gap was closed at the 49 m band, where the sensitivity of both radios seemed comparable (on a subjective basis - not measured), and the FM interference on the Grundig subsided somewhat. One advantage the Concert Boy has is a second band (K1 or SW1), which is a bandspread band for 49 m (5.9 -6.23 MHz). While this makes tuning easier, I still find the tuning mechanism somewhat stiff, yet springy and imprecise. More heat and grease needed, perhaps?

Testing longwave here in North America is pointless, so I'll discuss AM performance. The same FM feedthrough problem exists on the Grundig if, for some reason, you leave the telescopic antenna extended. Since the AM band uses the internal loopstick antenna, keep the antenna down when listening to this band. Otherwise, the Concert Boy once again becomes useless.

If you live in a fringe FM area, the Grundig has terminals on the back for an FM dipole, as well as a DIN input/output jack and a headphone jack. The Partner has the latter two only. Note that the antenna terminals are only for FM and will not improve shortwave performance.

I have to say that I think Grundig's engineers got a little lazy on this one by providing themselves with tons of room to stuff their electronics into, while not taking advantage of it to enhance front-end performance. This radio suffers badly from cross-band interference. If you want a room-filling kitchen radio for FM, though, this one may fit the bill.

The big Boy needs big batteries : 6 'D' cells