I've been searching for some hints as to what may be in the resin-encased
amplifier used on the Wellbrook loops without much luck. Their power demand
of 130 mA at 12 volts is kind of high for any FET diff-amp, PNP level shift,
into a balanced to unbalance output transformer arrangement. I'm using that
configuration right now on a tuned loop that only requires 17 mA at 9 volts.
Any ideas or links to useful information?

Thanks,

Chuck, w6pkp

"Chuck Olson" wrote in message
news
I've been searching for some hints as to what may be in the resin-encased
amplifier used on the Wellbrook loops without much luck. Their power
demand
of 130 mA at 12 volts is kind of high for any FET diff-amp, PNP level
shift,
into a balanced to unbalance output transformer arrangement. I'm using
that
configuration right now on a tuned loop that only requires 17 mA at 9
volts.
Any ideas or links to useful information?

Thanks,

Chuck, w6pkp

Hi Chuck,

The hi Ic is usually indicative of a CATV device being run in a hi IP3 mode.
The preamp I am using on my 7' shielded loop was originally published by
Burhans and described in the 1985 June Lowdown- using a J310 followed by a
2N3904 and a pair of Mouser audio tranformers both IN and OUT. The URL
appears to have gone away- I can send the schematic if you are interested.

Dale W4OP

"Dale Parfitt" wrote in message
news:RE5Wd.28241$uc.2783@trnddc09...

Hi Chuck,

The hi Ic is usually indicative of a CATV device being run in a hi IP3
mode.
The preamp I am using on my 7' shielded loop was originally published by
Burhans and described in the 1985 June Lowdown- using a J310 followed by a
2N3904 and a pair of Mouser audio tranformers both IN and OUT. The URL
appears to have gone away- I can send the schematic if you are
interested.

Dale W4OP

I'm very interested, Dale. I can read wmf, png, jpg, gif and pdf - - maybe a
few more. The png file is usually the most compact.

Thanks,

Chuck

The hi Ic is usually indicative of a CATV device being run in a hi IP3
mode.
The preamp I am using on my 7' shielded loop was originally published by
Burhans and described in the 1985 June Lowdown- using a J310 followed by a
2N3904 and a pair of Mouser audio tranformers both IN and OUT. The URL
appears to have gone away- I can send the schematic if you are
interested.

Dale W4OP

I'm very interested, Dale. I can read wmf, png, jpg, gif and pdf - - maybe a
few more. The png file is usually the most compact.

I'm interested also. Any chance that a Web-postable file could be
provided?


--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dave Platt" wrote in message
...
The hi Ic is usually indicative of a CATV device being run in a hi IP3
mode.
The preamp I am using on my 7' shielded loop was originally published
by
Burhans and described in the 1985 June Lowdown- using a J310 followed
by a
2N3904 and a pair of Mouser audio tranformers both IN and OUT. The URL
appears to have gone away- I can send the schematic if you are
interested.

Dale W4OP

I'm very interested, Dale. I can read wmf, png, jpg, gif and pdf - -
maybe a
few more. The png file is usually the most compact.

I'm interested also. Any chance that a Web-postable file could be
provided?

Maybe Dale can post it on alt.binaries.schematics.electronic - - okay Dale?