Ham Radio Homebrew Informations: Re: [HamBrewers] 144

Ranajay,

No TBA810 eh? that was a popular VU chip!

Let me add that this is a nice kit for anyone to build..

http://www.qrpkits.com/scoutregen.html

I built one and made some minor mods.

At 02-06-2011, you wrote:

Forgive me for being "outrageous" : but why not, just for the sake of it, try a 4-5 transistor 2m AM tcvr with Super-regen Rx for the bang of it? Oodles of sensitivity, horrible selectivity: I used a BF200 preamp + BF194 super regen detector + LM386 (oops Raj) for airband monitoring with a tuner varactor back to back for tuning back in 90s. The BF200 booster transistor at 9V 2mA prevented the reradiation. A simple 2 stage overtone oscillator BF194 + 2SC3355/2570 running class C and a series modulator makes the 20mw Tx...Could cover half a mile I guess. In the sixties, I guess this scheme with miniature 90V tubes was a popular project, no? Somewhat improved selectivity was achievable using a 3 pole helical LC filter in a copper foil enclosure, but for a single channel only. The only crittical thing was starting the quench: the super regen stage emitter RFC and the base decoupling caps are the tricks!!!!

--- On Wed, 6/1/11, rahul srivastava <lkorahul@yahoo.com> wrote:

From: rahul srivastava <lkorahul@yahoo.com>

Subject: Re: [HamBrewers] 144 - 146 Mhz (2M) Rx thoughts

To: HamBrewers@yahoogroups.com

Date: Wednesday, June 1, 2011, 1:53 PM

Great Raj,

For those interested the chip has some very interesting applications. To start with with one of this single chip you can homebrew a complete HF SSB rig, but now if that you are a true Hambrewer...!!!

73's

Rahul VU3WJM

--- On Wed, 1/6/11, Raj <vu2zap@gmail.com> wrote:

From: Raj <vu2zap@gmail.com>

Subject: Re: [HamBrewers] 144 - 146 Mhz (2M) Rx thoughts [2 Attachments]

To: HamBrewers@yahoogroups.com

Date: Wednesday, 1 June, 2011, 9:51 AM

Some data sheets attached.

At 01-06-2011, you wrote:

Hi! Raj,

MC13135 and its earlier variant MC3362 is still available at Delhi if anyone interested. Lately I stopped going in for complete discreet ones cause found it easier modify surplus items, but that barely scrathes the itch of a totaly homebrewed project.

73's

Rahul VU3WJM

--- On Wed, 1/6/11, Raj <vu2zap@gmail.com> wrote:

From: Raj <vu2zap@gmail.com>
Subject: [HamBrewers] 144 - 146 Mhz (2M) Rx thoughts
To: HamBrewers@yahoogroups.com
Date: Wednesday, 1 June, 2011, 9:08 AM

For two meters I would suggest the obvious "kiss" mode.

I will leave out the PLL/DDS part out of discussion for now. We have others who can suggest.

One chip of the series MC3357, 3359 and so forth.. will do the major task of conversion, limiting & detection! These devices are designed for cordless phones and are for NBFM.

Some thoughts:
You have the front end built in the later chips. Others require the first mixer e.g. 3357
Some chips require a discriminator coil/cap and others resonator.
10.7 or 21.4 Mhz & first IF 455 second IF (first IF depends on your junk box xtals)

Audio stage:
No more LM386 please. It took many years to get out of the clutches of LM380!
Now I suggest the TDA2822 stereo amp in push pull mode. I found this chip very
stable and took a lot of abuse. I got a great sound in my RX project. Cheap!

Hi,
I am also interested in this project.
I am also requesting VU2ZAP to give his thought in this regard.

with 73's
de VU2GAQ
Kumar Gautam
Ex- VU3KGL

--
Raj, VU2ZAP
Bangalore, India.

--

Raj, VU2ZAP

Bangalore, India.