Hate to reinvent the wheel- has anyone used the KK7B TX board on 455KHz?
What are you using for the power splitter and quadrature?

Tnx,

Dale W4OP

wrote in message
news
On Fri, 26 Dec 2003 05:02:55 GMT, "Dale Parfitt"
wrote:

Hate to reinvent the wheel- has anyone used the KK7B TX board on 455KHz?
What are you using for the power splitter and quadrature?

Hi Dale,

Two Ft37-43 wound as needed for the splitter. The turns ratio will
be 1:3 ( 5:15 turns)for the step down to 25ohms for the
autotransformer and the splitter will need to have enough turns to be
around 20turns bifilar. The center of the bifilar coil goes to the
tap point of the autotransformer. That will get you in the ball park.

The quad can be done using the same methods as shown for HF though the
C's and L's are much larger. If your using a fixed freq a R-C shifter
will work. The SBL-1 DBMs are only rated down the 1mhz on the LO
port so performance may not be as good. The SBL-1-1 or other DBM
will give better performance at 455khz.

Check Experimental Methods in RF Design for tons of Info. Also Google
"Phasing TX" and "Phasing RX". All of the phase shifters that work
for the R2 and MiniR2 (new Breed and others) will work for the T2 so
that should provide plenty of ideas.

I run a 20m miniR2 and T2 through a TenTec 1208(transverter) for 6m
SSB ops at times. Turns out to be the hottest 6m RX I have bar none.


Thanks Allison- some good ideas and areas to research. My intention is to
build what R.L. Drake called a "reciter" to go with my Davco DR-30 RX. The
Davco has on its rear panel, the 455 KHz BFO, VFO and heterodyne oscillator
outputs making this approach attractive.

73,

Dale W4OP

Allison
KB1gmx

wrote in message
news
On Fri, 26 Dec 2003 05:02:55 GMT, "Dale Parfitt"
wrote:

Hate to reinvent the wheel- has anyone used the KK7B TX board on 455KHz?
What are you using for the power splitter and quadrature?

Hi Dale,

Two Ft37-43 wound as needed for the splitter. The turns ratio will
be 1:3 ( 5:15 turns)for the step down to 25ohms for the
autotransformer and the splitter will need to have enough turns to be
around 20turns bifilar. The center of the bifilar coil goes to the
tap point of the autotransformer. That will get you in the ball park.

The quad can be done using the same methods as shown for HF though the
C's and L's are much larger. If your using a fixed freq a R-C shifter
will work. The SBL-1 DBMs are only rated down the 1mhz on the LO
port so performance may not be as good. The SBL-1-1 or other DBM
will give better performance at 455khz.

Check Experimental Methods in RF Design for tons of Info. Also Google
"Phasing TX" and "Phasing RX". All of the phase shifters that work
for the R2 and MiniR2 (new Breed and others) will work for the T2 so
that should provide plenty of ideas.

I run a 20m miniR2 and T2 through a TenTec 1208(transverter) for 6m
SSB ops at times. Turns out to be the hottest 6m RX I have bar none.


Thanks Allison- some good ideas and areas to research. My intention is to
build what R.L. Drake called a "reciter" to go with my Davco DR-30 RX. The
Davco has on its rear panel, the 455 KHz BFO, VFO and heterodyne oscillator
outputs making this approach attractive.

73,

Dale W4OP

Allison
KB1gmx