"Michael Black" wrote in message
ample.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.

I always start from scratch. I build my own PCB's, wind my own coils, metal
enclosures and chassis. If I was capable of making all my own components,
including tubes, I would sure would give it a go - real homebrew!

Nikon D3000 wrote:
"Michael Black" wrote in message
ample.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.

I always start from scratch. I build my own PCB's, wind my own coils, metal
enclosures and chassis. If I was capable of making all my own components,
including tubes, I would sure would give it a go - real homebrew!


A FRG-7 from scratch would make a good project for you!

War story...many moons ago I saw a brand new FT-757 at a hamfest
disassembled to the fullest extent possible. They had just hit the
market at the time. The story was that it was an evaluation rig and the
teardown was part of the evaluation. They only wanted $100 for the
pieces and I was tempted to grab it. A 757 Kit - haha.

Then common sense clicked in. What if it is missing a couple of crucial
pieces?

-Bill

In message , Bill M
writes
Nikon D3000 wrote:
"Michael Black" wrote in message
news:Pine.LNX.4.64.1009232232010.18476@darkstar. example.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.
I always start from scratch. I build my own PCB's, wind my own
coils, metal enclosures and chassis. If I was capable of making all
my own components, including tubes, I would sure would give it a go -
homebrew!
A FRG-7 from scratch would make a good project for you!

War story...many moons ago I saw a brand new FT-757 at a hamfest
disassembled to the fullest extent possible. They had just hit the
market at the time. The story was that it was an evaluation rig and
the teardown was part of the evaluation. They only wanted $100 for the
pieces and I was tempted to grab it. A 757 Kit - haha.

Then common sense clicked in. What if it is missing a couple of
crucial pieces?

The same caution should be exercised when buying second-hand jigsaw
puzzles.
--
Ian

"Bill M" wrote in message
...
Nikon D3000 wrote:
"Michael Black" wrote in message
ample.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.

I always start from scratch. I build my own PCB's, wind my own coils,
metal enclosures and chassis. If I was capable of making all my own
components, including tubes, I would sure would give it a go - real
homebrew!
A FRG-7 from scratch would make a good project for you!

I could quite possibly design and build a far better receiver than the FRG-7
anyhow!
Manufacturers build to a design price - so inevitably compromises have to be
made to keep within budget.
As a lone constructor, that restriction doesn't even enter into the equation
when I design and build. The only problem I sometimes find is when certain
components become obsolete and consequentially unavailable, so then it
becomes a case of "back to the drawing board!"

Bill M writes:
....[lots snipped]....
War story...many moons ago I saw a brand new FT-757 at a hamfest
disassembled to the fullest extent possible. They had just hit the
market at the time. The story was that it was an evaluation rig and the
....[more snipped]....

When I was in college (many moons ago), one of my HAM classmates
disassembled Collins transceivers to get parts for his hombrewing!
And when he was finished, they even looked nice (X-Y wiring, etc.)

Me? I take old TV's apart.

-- Myron A. Calhoun
--
-- Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety
Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license

Nikon D3000 wrote:

"Michael Black" wrote in message
ample.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.

I always start from scratch. I build my own PCB's, wind my own coils, metal
enclosures and chassis. If I was capable of making all my own components,
including tubes, I would sure would give it a go - real homebrew!

http://paillard.claude.free.fr/

Rob wrote in
:

Nikon D3000 wrote:

"Michael Black" wrote in message
ample.net...
On Thu, 23 Sep 2010, Nikon D3000 wrote:

Some folks just can't leave well alone!

Another way of looking at it is that a commercial receiver makes
a good start at a semi-homebrew project.

I always start from scratch. I build my own PCB's, wind my own coils,
metal enclosures and chassis. If I was capable of making all my own
components, including tubes, I would sure would give it a go - real
homebrew!

http://paillard.claude.free.fr/


Well! Do some folks REALLY thing that an FRG-7 is good enough as it
stands!!!
First and most important problem, lousy selectivity, about 6khz BW with
very poor shape factor.
Secondly very poor AGC performance, this can easily be improved with an
HCD as AGC detector and better biasing of the AGC stage and detector.
Thirdly not very good RF noise and linearity performance. Easily improved
with a better FET, better biasing and introducing an RF gain control in
the G2 circuit, while keeping AGC action on the stage.
Finally too fast a tuning rate for easy SSB tuning. I am investigating
mods to the tuning mechanism to give me another 5 times slower rate.
BTW I have made 8 complete homebrew ham stations in my career and have
WAC and about 160 countries with them.
This INCLUDES receivers.
Admittedly an Xtal controlled CIO is a luxury, but I had found a not
inconsiderable drift in the original SEO oscillator that I had rather do
without. As has been said it makes the basis of quite a good receiver,
once a few bugs are removed.
After the RF stage my next target will be the first balanced mixer. It
looks to me as if the stage could be set up to reduce intermodulation
quite a bit.
However at my age starting right from scratch is not so easy so turning
a leather purse into a silk one is easier and quicker. My TS-820 has had
the same treatment and now runs ALL HF bands.
&#'s Cliff Wright