[BC] Secondary & Tertiary Tone

[Peter Smerdon]

Yep - remember them well.
We had a bunch of them in newsroom, where the quick recueing of carts 
was a real boon - though some of the Fidelipac (Fiddlypac) carts would 
really rattle in fast forward. Soon moved to quieter Audiopaks.

However their audio performance left something to be desired.
That was a real problem at a time (in Australia), when we had annual 
engineering inspections by the Govt regulator - where they did audio 
performance tests on most station gear.
The RapidQ's could barely meet the required spec in S/N (<-50dB wrt peak 
flux)and Wow & Flutter (<0.2% unwtd RMS - remember W&F?).
I recall the FCC's specs were less onerous than ours, which ocassionally 
caused a problem with equipment imported from the US.

I'd resort to carefull tweaking of the machines on the day before the 
inspection (we usually got a week's notice), and hoping they held spec 
long enough to pass muster.
I eventually solved the S/N problem by discovering that lifting the top 
lid  dropped the noise floor by 5-6dB. The noise was all 50Hz (mains 
frequency). It must have been some kind of mains induction in the 
alunimum case. I replaced the lids with smoked acrylic. Problem solved!
I (sorta) solved the wow & flutter problem by etching the (normally 
mirror-smooth)capstans in battery acid. Got them in the ball-park, but 
with those little DC motors (with thier commutators and brushes)they 
were always marginal.

Harold, you'll have to stop reminding me of these equipment nightmares ;-)

Harold Hallikainen wrote:

> 
> Speaking of carts, anyone remember the Garron (Ron's Garage) Rapid Cue
> machines? I think these were actually a pretty sophisticated design for
> the 1970s. After EOM, they'd run fast until they heard anything on the cue
> track. Ideally, what they heard was the sped up 1kHz, so they'd stop. So,
> the stop cue detector was, instead of 1kHz band pass, a 1kHz high pass
> filter. This caused a problem for my logging system, which ran 3.5kHz FSK
> between the primary (1kHz) and secondary (250Hz) cues. As soon as logging
> would start, the cart would stop. So, I had to add low pass filters so
> they would not hear the logging data.
> 

Cheers,
-- 

Peter Smerdon.

Melbourne, Australia.