Allison,
I got the RF2065s as substitutes for the MAR-3/MSA-0385, so that's my
problem. I was able to actually get some real MAR-6s, but I need a
couple of the MAR-3 or substitutes. Not a bad deal on the RF2065s; 25
of them for $9.95 plus a little for shipping. I needed the data sheet
just to convince myself that they'll really work.

I have another problem...now I can't find the ten MAR-6s that I bought
earlier! Creeping old age, or something I guess! Unfortunately, they
were shipped in a plain white business envelope, and they could very
well be hiding in plain sight.

I like your point on the discrete transistor substitution as well.
I'll keep that in mind. I have plenty of room on the board, as I'm
building only the transmitter and PA chain (for 21 MHz), not the VFO
and receiver as shown in the figure.

Thanks,
Ted

On Sat, 18 Mar 2006 03:58:30 GMT,
wrote:

On Fri, 17 Mar 2006 18:48:51 -0500, TW
wrote:

I need a datasheet on the RF2065 MMIC, or more specifically,
RF2065TR7M. Supposed to be similar to the MAR-3, but I can't prove
it. The guy I bought some from tested it as if it were a MAR-3, he
says.
---snip---

For that application at 18mhz there is plenty of room for subs. The
mar3 or something reasonably close will be fine. You only need
enough gain to set the noise figure byb offsetting the losses in the
DBMs and image stripping filters.

--snip---
Or it's so old everyone forgot they made it! Really, it does
happen!!!

For circuits in EMRFD using MIMICs all you need to substitue them is:

Gain
Max power out
Noise figure

Then order the nearest MAR or ERA part from Minicircuits.

Or as I've done in many cases is use a 2n3904 (2n5109
if more bandwidth is needed) in a broadband 50ohm amp
circuit (from earlier in the book). Same performance
and I can build from my parts bin and tweek it for my usage.
I save the mmics for where space or frequencies greater than
100mhz are important to me.

Most cases the lattitue is fairly wide and the specific circuit
details will call out the needed info to apply it.


Allison