Behold, John Miles scribed on tube chassis:

In article gzgQd.58975$L_3.40931@clgrps13, says...
IMHO, it would be of benefit if the no-code class, rather than limit
one to commercial based equipment, be forced to use homebrew TX or RX
equipment.

The only requirement being a power limitation and it meets the spectral
purity, etc. regs of the country of origin. Boatanchor or
"radio-on-a-PIC", whatever construction.

But you know the government..........


Somehow, I doubt many of those 20 WPM Extras making equine posteriors
out of themselves on 75 fone are doing so on homebrew rigs.

The idea is the advanced ticket people can buy commercial rigs.

I was reading some of the the history of Ham radio though and it seems
today's ham's rarely fit the bill :-(

What happened?

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*

Latest project here is a HF transmitter, 8" X 15" X 13", the same size as
the old Sony surround amp put up in the loft 7 years ago.


RRH.
"Airy R.Bean" wrote in message
...
Much of the negativity that the CBer-Masquerading-As-A-Radio-Ham
emits when it is suggested to him that he should build his own rig comes
from a complaint that it is not possible to miniaturise a rig to the sizes
that are available from the Nipland CB suppliers, mainly Yaesu and
Kenwood.

But, surely, the size of a rig is irrelevant to anyone interested in
technical
performance?

I wonder what size of rig is really acceptable to the _REAL_ Radio Ham
when
you consider that the RACAL RA17 was a large 19" rack model, and
when you take into consideration the footprint of desktop PC's that have
been welcomed so recently into a number of shacks?

How about a foot print of between 12" and 18" square, with a height of
about
3"?

That would make a rig about the same size as a DVD player, again, an item
of consumerist products that until recently was unknown but now is de
rigeur - again
pointing out the spurious argument put up against HB.

In a box 18" square by 3" tall, we'd have enough room to manoeuvre and to
experiment with circuit changes but without worrying that our Henley
"Solon"
soldering irons were going to melt a component other than the one we're
currently dealing with.

Airy R.Bean wrote:

But, surely, the size of a rig is irrelevant to anyone interested in
technical
performance?

I wonder what size of rig is really acceptable to the _REAL_ Radio Ham when
you consider that the RACAL RA17 was a large 19" rack model, and
when you take into consideration the footprint of desktop PC's that have
been welcomed so recently into a number of shacks?

How about a foot print of between 12" and 18" square, with a height of about
3"?


I understand your sentiments. The trend of making rigs very small can also make them more
difficult to use. As an example of a rig that is more compact than most commercial off-the-shelf
ones, look at the Elecraft range. I love the performance of my K2. However, the front panel size
means that each key is often performing at least 2 different functions, sometimes 3. Many on the
Elecraft reflector have expressed a desire for a larger FP when more functions could be available
by dedicated buttons. So I think that ergonomics comes into play. For even higher component
density, again mostly with discrete components, look at the KX1. A fun cw qrp tcvr to build. So
it's not always the case that HB rigs have to be very much larger than commercial rigs.

I think much depends on your intended usage. For a base station, as you point out, size doesn't
matter that much. I don't think anyone would claim that the IC7800 or FT1000MP was a small rig.
Your suggested size would be fine with me for a base station. For portable, field-day or for
mobile or even pedestrian mobile operation, size and current consumption are important attributes,
and often some performance and ergonomics are sacrificed in the trade-off for smaller size. Your
proposed size would probably be too large for such usage - perhaps, something in the region of a
quarter of that volume would be more appropriate.

Another factor is the extent to which you want to remodel the rig after experimentation. I think a
lot of HB tends to end up larger because it was prototyped using construction techniques (such as
ugly bug) that are good for prototyping and changes, but then when the design has iterated to
something near optimal, it is never rebuilt using denser construction such as double-sided PCB.
Perhaps it's a case that the constructor has got their satisfaction with design and are less
motivated by better engineering its construction. I know that some are and like to aim for more
production quality, often taking as much time in that area than the original design and
prototyping. However, I suspect that they are in the minority.


73, David M0DHO

The correct size for homebrew equipment is the following:

1) The size that you feel most comfortable with. Many individuals do not
want to duplicate the ultra compact construction methods that electronics
corporations use. That is hard and tedious work, for sure, done by people
who are experts in that area. Those nifty little boxes that we buy began
life spread out and haywired together over a large table top. I have been
through that many times.

2) The goal that you have in building your own equipment. Many folks
consider their homebrew equipment as "test beds" for future experimentation,
refinement and possible redesign. I am one of those, and an example is on
QRZ.COM (W0IYH). If you build this gear as a very compact "ship in a bottle"
project you are pretty much "locked in" to whatever you come up with. Major
modifications become doubly major projects.

3) The average amateur, working in his basement (that's me) has a very
lengthy and arduous task to duplicate what a room full of engineers do for
a living. Not only that, those folks very often don't redesign everything
from scratch, they improve and redesign iteratively over several years,
building on what they have done on previous models.

4) Finally, there is a big difference between a) duplicating a published
design and b) struggling with your own (and possibly unique) design. In the
latter case we need hardware and software that are easily accessible.

The experimenter's code is "Nothing is permanent".

Bill W0IYH


"Airy R.Bean" wrote in message
...
Much of the negativity that the CBer-Masquerading-As-A-Radio-Ham
emits when it is suggested to him that he should build his own rig comes
from a complaint that it is not possible to miniaturise a rig to the sizes
that are available from the Nipland CB suppliers, mainly Yaesu and
Kenwood.

But, surely, the size of a rig is irrelevant to anyone interested in
technical
performance?

I wonder what size of rig is really acceptable to the _REAL_ Radio Ham
when
you consider that the RACAL RA17 was a large 19" rack model, and
when you take into consideration the footprint of desktop PC's that have
been welcomed so recently into a number of shacks?

How about a foot print of between 12" and 18" square, with a height of
about
3"?

That would make a rig about the same size as a DVD player, again, an item
of consumerist products that until recently was unknown but now is de
rigeur - again
pointing out the spurious argument put up against HB.

In a box 18" square by 3" tall, we'd have enough room to manoeuvre and to
experiment with circuit changes but without worrying that our Henley
"Solon"
soldering irons were going to melt a component other than the one we're
currently dealing with.

The correct size for homebrew equipment is the following:

1) The size that you feel most comfortable with.
The experimenter's code is "Nothing is permanent".

Bill W0IYH

GM Bill, good to hear you up and about. The curmudgeon (Sorry all you
curmudgeons for the insult) that started this thread hasn't the common sense
or native intelligence to pose the question. He's just there to troll and
present his agenda that he is better than others. Obviously the answer is
"as big as it needs to be to house the intended materials" and not the other
way around. I put the poor soul in my plonk box some time ago and hadn't
seen hide nor hair of him in some time until your byline showed up.

I still haven't found my stray resonance in my MRF-150's that causes the
gain dip at 32 MHz. Haven't looked real hard for it since it's so eminently
flat from 2-30, it's just that it's also useable on 50 MHz and there's just
a little 4 dB droop that comes right back up above 35-36 MHz. What with the
state of the solar cycle, and with what my age for the next one will be, I
suspect I shouldn't be so concerned about it.

I know that with your design philosophy, your 150's are going to last
forever, but just in case you ever get a thunderstorm in CR that does you
dirt, there's an awfully good buy running around on E-Bay at the moment. ERB
Engineering built the solid drivers for the tube amps for MRI machines and a
large number of them have turned up on the surplus market. They include a
pair of MRF 150's as well as a LOAD of other goodies and usually go for less
that the price of a singleton. They don't have the matched pair codes, and
with the computer controlled bias the way they set them up they can get away
without them, but they DO have the same batch codes on both the ones I
bought. Search on MRF-150 amplifier.

Regards

W4ZCB

On Tue, 15 Feb 2005 08:18:47 -0000, "Airy R.Bean"
wrote:

But what of the "liebebstraum" (sp?) for future experimentation
with the circuitry?


Hate top posting, you always loose the question.

Since I do experiment and modify I allow for it. I enjoy building
small. Since many of my designs are elaborate I've gotten used to
working in small spaces and laying out circuits for accessability and
considerations for possible future changes.

Sometimes I will work around an existing package. I have a number of
of old computer serial A/B switches. They are aluminum with a rounded
side top and bottom shell. The front and rear plate form a simple
frame to screw the case into one unit. It's a trivial task to make
replacement front and rear as the original have too many holes. I got
these for free when a local merchant decided they were of
insufficient value to store for sale.

My latest project is a 5Wpep SSB tranceiver for 6M band in a package
thats only 2x5x7 inches with PLL tuning and digital display. The pll
module is only 1.5"x1.5"x1" constructed dead bug on pcb material
which also forms the case/shield. It could be made smaller but,
that was adaquately small for this project. The power amp is three
transistors of VHF types and fits in a strip of 1.25"Wx 2.5"L x1.5H
excluding heatsink(case is aluminum). For 10mW in I get 5W pep
with good IMD. The front end (rf amp, mixer and mixer amp ) is
complete [1x1x1..25"] and is both compact and very low noise.
The bandpass filter assembly and the crystal filter IF amp sections
are done too. The rest will easily fit in that box obviously.

When doing this I have to consider mechanical things like connectors,
controls and other parts that may be physically large compared to the
circuits they control. For example the froont pannel has to to have
a volume control, RF gain, tuning , microphone jack, headphone jack,
frequency display and meter for RX signal and tx power all in 2x5
inches. The RF gain and volume will have to be a dual (coaxial)
control to fit it all. As you can see getting all the knobs in place
can be more difficult than the electronics behind it.

The only components that will not be in the box will be microphone
dattery and antenna. I exclude the antenna (portable 3 element beam)
and battery power as this is an excusion radio. A 10AH battery of the
gell electrolyte type will be adaquate for a 24 hour field use.

Small is not hard and doesn't contradict high perfomance.

Allison
KB1GMX

I understand your sentiments. The trend of making rigs very small can also
make them more
difficult to use. As an example of a rig that is more compact than most
commercial off-the-shelf
ones, look at the Elecraft range. I love the performance of my K2.
However, the front panel size
means that each key is often performing at least 2 different functions,
sometimes 3. Many on the
Elecraft reflector have expressed a desire for a larger FP when more
functions could be available
by dedicated buttons. So I think that ergonomics comes into play. For even
higher component
density, again mostly with discrete components, look at the KX1. A fun cw
qrp tcvr to build. So
it's not always the case that HB rigs have to be very much larger than
commercial rigs.
=============================
A example of good ergonomics are the Watkins & Johnson commercial receivers
, in a 19 inch enclosure with a large functional front panel. Inside a tiny
switch mode power supply and a few small PCB modules ; the box being about
half empty .

Same with my old TenTec Paragon transceiver ,a large enclosure with
ergonomical FP and separate cable linked modules inside.
Also for homebrew equipment using a relatively large enclosure ,you have a
large FP and oodles of space to fit separate screened modules which can be
individually tested (building block method). The RF modules based on 50Ohms
IN and 50Ohms OUT can be readily interconnected with ready made short coax
leads with SMA or similar connectors . These links can be found at flea
markets , probably surplus leftovers from the mobile phone industry.

Frank GM0CSZ / KN6WH

On Tue, 15 Feb 2005 06:23:08 GMT, Gregg wrote:

IMHO, it would be of benefit if the no-code class, rather than limit one
to commercial based equipment, be forced to use homebrew TX or RX
equipment.

We have far to many appliance ops.

The only requirement being a power limitation and it meets the spectral
purity, etc. regs of the country of origin. Boatanchor or
"radio-on-a-PIC", whatever construction.

That exists already/

Here in the USA:

Tech limited to bands starting at 6M (50mhz) and up to whatever.
Power is 1500 max, any mode, build, modify or buy. No CW required.
All modes permitted unless restricted by band use, SSB, FM, Fastscan
TV, Data/digital, and even CW. Even if you have not taken the CW test
and you think you can do it you can use it.

Tech+ same as above with code, limited access to some of the HF
bands.

General same as Tech(all permitted modes per band), required 5wpm
code and grants access to the MW and HF bands (160 thru 10).

Extra all of general privledges plus acces to some of the subbands.

Allison
Kb1GMX

On Tue, 15 Feb 2005 13:35:55 GMT, "Highland Ham"
wrote:

modern tranceivers.
Yes most of the current generation radios (FT817, IC706MIIG, and
friends) with their menus and all are quite annoying to me. I only
have a few commercial radios other than HTs. My favorite is a
25 year old IC245 (2m FM/SSB/CW) and the other a Tentec 526(6n2 meter
SSB/SM/CW radio) as both don't have menues.

Much snippage-----
large FP and oodles of space to fit separate screened modules which can be
individually tested (building block method). The RF modules based on 50Ohms
IN and 50Ohms OUT can be readily interconnected with ready made short coax
leads with SMA or similar connectors . These links can be found at flea
markets , probably surplus leftovers from the mobile phone industry.

I happen to like that mode. Also testing with a 50ohm path is easier
and can make it possible to build simple test fixtures on the bench.
I build modues usually using PCB material soldered up and test each
stand alone. The beauty is you can optimize that function and if at a
later date you wich to try different it can easily be remove and a new
design substituted. Also shielding is inherent, that alone in many
cases is a performance improver. Testing is easy on the bench
as nothing has to be mounted to work and once satisfied you transfer
the modules to a practical package. Repair show somethign fail is
simplified as you can remove the offending module and fix or outright
replace it by building another, and maybe improving it.

Allison
KB1GMX

On Tue, 15 Feb 2005 13:09:37 GMT, "Harold E. Johnson"
wrote:

I still haven't found my stray resonance in my MRF-150's that causes the
gain dip at 32 MHz. Haven't looked real hard for it since it's so eminently
flat from 2-30, it's just that it's also useable on 50 MHz and there's just
a little 4 dB droop that comes right back up above 35-36 MHz. What with the
state of the solar cycle, and with what my age for the next one will be, I
suspect I shouldn't be so concerned about it.

I'd take a look and a grounding issue. Last I played with MRF150s I
forgot to ground the top to the bottom side of the board right where
the leads intersect (the hole wher ethe MRFs meet the heat sink).
A peice of .003 copper shim stock from the top to bottom at the hole
fixed it along with a few places in the board (#18 wires from top
ground to bottom ground) seemed to clean it up. Then I first
encountered the problem I thought it to be a device lead length
problem on the input or output. HIgh RF current at low imedences
can really show things you'd never notice at lower power.

Allison
KB1GMX