Apr 29, 2008

That 'other' radio hobby...

"FIRATO" at the RAI exposition in Amsterdam

From 1950 till 1998 the Amsterdam RAI expos
ition centre hosted the Firato every two years. This was a consumer electronics show, mainly focussing on Hi-Fi and TV&Video.
Several new introductions took place at the Firato, like:
  • 1963: The second national Television Channel (NED 2)
  • 1963: The Philips Compact Audio Cassette
  • 1967: Colour television by Philips
  • 1978: Text view by the BBC
  • 1982: Compact Disc by Philips
From the 90's onwards, people slowly lost interest in Hi-Fi and TV/Video. Home computer slowly took over...
During the period 1978 till 1985 I had a great interest for Hi-Fi. Every show I dragged tons of folders and stuff :)
I have been drooling at the top models of Philips Hi-Fi equipment, which at that time were accordingly high priced. Definitely not in my league, not even with my saturday-job at the local gas-station. It was mainly Akai I could afford and which suited me very well.

From early 2006 onwards I have slowly started collecting some of those legacy Philips products.
Local Flea markets and internet are superb for this. Even E-bay is useful, as I have collected rare Philips products for only 25 euro. These beautiful products did cost some 700 euro, back in 1979.

Philips AM/FM tuner type 22AH105 and Amplifier type 22AH308

The second CD-player ever: CD300, a second '105'tuner and a receiver 22AH306.
There is more; like a record player and , and.....etc.

Short note: this is all in my shack. Not the living-room.

Dating from 1978; the 22AH794 receiver, accompanied by the '541' Motional Feedback active loudspeakers (1976).
I own several 'Philips MFB' loudspeakers. What makes these special is that the typical non-wanted woofer cone movements (in and out-swing )
on bass impulses, are monitored by a small element and feed back into its internal amps. The result is a very clean and low base performance.

Is there some HAM related stuff involved here??

Yes some, because for receiving FM stereo in good quality you need an outdoors antenna nowadays.
For our 2007 holiday we built a 5el yagi (K6STI design:http://www.ham-radio.com/k6sti/small.htm).
It is now on my roof and serves me well for receiving distant FM radio stations in the range from NNE to South. Its clean pattern and a stone roof on its back does help as it ignores
all the local commercial stuff and brings out stations from 150km distance and beyond.
While enjoying the flexibility of a good directional antenna it does have its disadvantages too.
Switching direction to the other favourite station, needs digging out that old rotor control unit and takes ages of time. Now I also have several tuners, which I want to feed as well.

An old VHF vertical was found on a flea market. Its a typical fibreglass version of 1mtr length. Inside I found a small burned ceramic cap. That's also 'typical', as some operators never read the specs.
I tuned this one into a FM radio GP with only 1 radial, made from some brass length.
In my collection of more flea-market stuff I found a small aluminium side mount. Neat !
Last weekend offered lovely sunny weather. I mounted the new omni-vertical to the existing FM antenna setup. Two different coaxes enter my house just at the point where both tuners are located in my shack.

This K6STI type FM radio antenna was made from alum and 40mm PVC pipe. A true home made 1:1 balun is installed to keep the pattern clean. This antenna is easy to build and does a wonderful job.
It was used during our 2007 holiday activities in HB0 .

The new vertical is just parallel to the mast, on the right side.

The vertical was painted black with some 'green spots'.
The radial and mounting bracket were painted too, all just to lower the visual impact.

Does it work?
Yes, the vertical offers my favourite local stations (e.g. Classic Arrow Rock radio) in a range of max 50km. It does not offer the 'FM-DX' like the yagi does. Very, very few stations can be heard and those have S1 and R2-3 only...
But on domestic reception of FM stereo radio stations it performs as expected.

You can never have too many antennas.


1 comment:

Gerard Vink said...

Nice to see another 22AH794 out there in the wild. Mine has a black front (type 22AH794/90R). I noticed different designs of the switches on this receiver has been produced over the years (guess the Philips designers couldn't decide). To bad your image is so small, I cannot see what yours look like...