READ THIS! SKS system... cops almost hauled me off

Tom

Let's not forget that as a legitimate, incorporated consulting engineer, you have access to many lucrative, entirely legal, tax loopholes. My problem is turning down clients due to workload, so in the long run the honest, legitimate way of doing things is always better

Not to mention that you are far less likely to experience a terminal wound cavity

jay

 

Hi Abq_sfr,

Yea, this is most likely a poor receiver in the dye-pack tracker. Such receivers are made to be very sensative, but in a downtown area very sensitive revievers will almost always overload.

This is why police VHF and UHF radios were so expensive, as they had very big and bulky filtering, and due to the filtering, they could run much higher power local oscillators. These two things together is what helps improve the off-frequency and nearby large signal handling capabilities of the receiver.

But a lightweight, mobile tracker is not going to have these things. So a nearby FM broadcast station is going to blow right through the modest 216.5 MHz front-end filter, and ends up at the mixer within a few dB of the local oscillator power. Which then results in the FM signal acting as a second local oscillator in the receiver mixer. This allows all sorts of odd frequencies to be mixed into IF (Intermediate Frequency) amplifiers besides 216.5 MHz.

I remember another incident where such a receiver was used in the wrong application. A helium baloon used a low-power pager reciever, as the designers wanted to keep the power budget low. But the local oscillator power was so low, that when the baloon got up at 100 K feet, it saw all the signals from Milwaukee Chicago and Mineapolis, and every small city inbetween. The receiver was completely swamped, and the resulting retransmitted audio was just a mish-mash of tones and beeps. Totally useless. Worse yet, the controls came in through such a receiver. So, the operators could not dump the helium when it got near a metro area. I helped track the baloon, and based on my report of bearing and elevation another person visually spotted it out west of Elgin, IL in the stratosphere just after dusk. It rose up until it burst. At whcih time the optical observer lost track of it. When it got closer to the ground mobile teams tracked it down, until they all convergered on Ohare airport from three directions. After apprising the FAA of the situation, one team was escorted onto the space between the two main runways and recoverd the baloon, where it had fallen.

 

opcorn: