On Thu, 6 Dec 2012 00:45:17 -0800 (PST), Dana wrote:

On Tuesday, December 4, 2012 6:54:15 PM UTC-8, Arid ace wrote:

My error - the IC mentioned should be SL612C and nowadays it's available from

China via eBay:

http://www.ebay.com/itm/120922014405... 4.m1497.l2649

It has a much wider AGC range than the TL026, up to 70 dB IOW higher than the

stage gain.

Let's see. SL612, $8+ each. TL026 $1.50 each.
-3dB bandwidth - SL612 up to maybe 15MHz. TL026 up to 50MHz.
SL612 AGC range 70dB, gain of 34dB. TL026 AGC range 50dB, gain of 38dB.
SL612 obsolete. TL026 in production.

An AGC range far in excess of stage gain isn't much use if the stage
is overloading anyway.

Why again would I consider the SL612? :-)

Dana K6JQ

The data sheet of the TL026 doesn't mention the maximum input signal that can be
processed. For the SL612 that is 250 mV rms. Then there's the supply current:
less than 5 mA for the SL612 but for the TL026 it's 6 times as much. Not to
mention the issue of stability.

For an IF higher than 10 MHz, the SL611 has -3 dB at 80 MHz and for the SL610
that is 120 MHz. On SW, an IF amp with low NF allows for a passive mixer as
long as the overall NF stays below ~10 dB. The SL612 has a 3 dB NF and a passive
mixer like the VAY1 a loss of ~ 5.5 dB so even with some input filter losses,
one can design a radio with high dynamic range, low power consumption and NF
10dB. Who would need a TL026? :-D

Jan