Message	Date	From	Subject
1665	2008-05-24 07:29:46	bkopski	EXPERIMENTAL METHODS - THE HARDWARE PART
Hi All - About two years ago I began putting together an HB 20 M SSB rig based in part on the popular BITX design. But since this transceiver would be my first SSB experience - I wanted first to build, test, modify, etc. each functional block by itself and then interconnect them to ultimately form the transceiver. I needed a simple low cost way to do all this experimenting and "interconnecting" and I chose to use RCA (phono) connectors to aid in this. The resulting module-by- module transceiver worked out very well. Since then I've done a lot of varied experimenting with other stuff and I continued to employ the same RCA connector concept. Now however instead of building a final item out of the modules themselves, I've come to use the module idea all by itself. Over time I've accumulated many connectorized functional blocks that have allowed me to more easily configure and evaluate a wide variety of rf designs before committing to a final assembly. Think of these functional blocks as child's blocks both are fun to build and then build again - with! Examples of individual functions include pads, terminations, an RLB, amplifiers (EMRFD Table 2.2, SSD p147), MiniCircuits amplifiers, a wide variety of filters, a crystal test fixture, mixers, product detectors, 2:1 transformers, and so on. A partial collection is shown in a photo as is one EMFRD amplifier. Also shown is a ~1 100 mHz rf sweeper design "strung out" on my bench using some of these interconnected building blocks. Ultimately I hope to build the final boxed-up sweeper using similar subcircuits but now assembled all together in a single assembly and thus liberate these connectorized modules for use in the next puesuit. BTW the board mounted RCA females are Mouser 161-4216 which work very well in this application. (My last purchase was for 100 pieces!) And as pictured, there are a wide variety of RCA-type connectors and adaptors available. I've also settled in on a simple board power connector based on male (on the board) and female (on the cable) pieces of 0.1" strip connectors. It all makes this kid's blocks very easy and fun to play with! Cordially, Bob K3NHI

Hi All -

About two years ago I began putting together an HB 20 M SSB rig based
in part on the popular BITX design. But since this transceiver
would be my first SSB experience - I wanted first to build, test,
modify, etc. each functional block by itself and then interconnect
them to ultimately form the transceiver. I needed a simple low cost
way to do all this experimenting and "interconnecting" and I chose to
use RCA (phono) connectors to aid in this. The resulting module-by-
module transceiver worked out very well.

Since then I've done a lot of varied experimenting with other stuff
and I continued to employ the same RCA connector concept. Now
however instead of building a final item out of the modules
themselves, I've come to use the module idea all by itself. Over
time I've accumulated many connectorized functional blocks that have
allowed me to more easily configure and evaluate a wide variety of rf
designs before committing to a final assembly. Think of these
functional blocks as child's blocks both are fun to build and
then build again - with!

Examples of individual functions include pads, terminations, an RLB,
amplifiers (EMRFD Table 2.2, SSD p147), MiniCircuits amplifiers, a
wide variety of filters, a crystal test fixture, mixers, product
detectors, 2:1 transformers, and so on. A partial collection is
shown in a photo as is one EMFRD amplifier. Also shown is a ~1 100
mHz rf sweeper design "strung out" on my bench using some of
these interconnected building blocks. Ultimately I hope to build the
final boxed-up sweeper using similar subcircuits but now assembled
all together in a single assembly and thus liberate these
connectorized modules for use in the next puesuit.

BTW the board mounted RCA females are Mouser 161-4216 which work
very well in this application. (My last purchase was for 100
pieces!) And as pictured, there are a wide variety of RCA-type
connectors and adaptors available. I've also settled in on a simple
board power connector based on male (on the board) and female (on the
cable) pieces of 0.1" strip connectors. It all makes this kid's
blocks very easy and fun to play with!

Cordially,
Bob K3NHI