BCD436HP Repair Notes

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KB2RSK

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Serial Notes
IF UNIT IS TO CLOSE TO A TRANSMITTER, MAKE SURE SCANNER IS NOT RECEIVING THE SAME FREQUENCY BEING TRANSMITTED

I sent my BCD436HP in for repair as it stopped receiving.

Attached are the notes I received back from repair.

I thought that searching for close by transmissions was an option for this scanner. Apparently not ??

Any comments ??
 

mikewazowski

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What were you doing with it when the front end got fried?

There's "searching for close by frequencies" and then there's "frying the front end by keying a radio up close to the antenna"
 

JamesO

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IF UNIT IS TO CLOSE TO A TRANSMITTER, MAKE SURE SCANNER IS NOT RECEIVING THE SAME FREQUENCY BEING TRANSMITTED

I sent my BCD436HP in for repair as it stopped receiving.

Attached are the notes I received back from repair.

I thought that searching for close by transmissions was an option for this scanner. Apparently not ??

Any comments ??
Near field RF can be very strong.

Even if the scanner is not on the same frequency being transmitted the front end can be fried.

General rule I use, do not have a transmit antenna within 25 feet of a receiver if at all possible. You can have them closer, but 25 feet will usually be a safe distance.

This obviously does not pertain to high power broadcast antennas, but if you are within 25 feet of a broadcast antenna under full power the scanner will be the least of your worries!
 

KevinC

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Serial Notes
IF UNIT IS TO CLOSE TO A TRANSMITTER, MAKE SURE SCANNER IS NOT RECEIVING THE SAME FREQUENCY BEING TRANSMITTED

I sent my BCD436HP in for repair as it stopped receiving.

Attached are the notes I received back from repair.

I thought that searching for close by transmissions was an option for this scanner. Apparently not ??

Any comments ??
Close is a relative word.

If you transmit on 154.00 with 1w (+30 dBm) the path loss at 1 foot is only about 6 dB, giving you a signal strength of +24 dBm. Most test equipment I have can't handle over a +20 at the antenna input. Transmit at 5w (+37 dBm) and it's +32 dBm...probably waaay too much.
 

JamesO

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Close is a relative word.

If you transmit on 154.00 with 1w (+30 dBm) the path loss at 1 foot is only about 6 dB, giving you a signal strength of +24 dBm. Most test equipment I have can't handle over a +20 at the antenna input. Transmit at 5w (+37 dBm) and it's +32 dBm...probably waaay too much.
And most test equipment does not have low noise sensitive first stage amplifiers, as most test equipments is not designed to be a sensitive receiver. Usually the unit under test is cabled directly test equipment to a coupler or test device. Some test equipment can take a direct transmit level from handheld or lower power mobile equipment.
 

KB2RSK

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repaired bc436hp

I was just monitorig when it quit.
Using an outside discone antenna.
My ham equipment was powered down. Not transmitting..
Could of been a static disharge.
Glad; it was still under warranty
 
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