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I have access to a large industrial shear that I use to cut larger pieces
of mostly .040 aluminum. For cutting on a table saw I like to sandwich the
aluminum between pieces of scrap wood or plywood. A couple of reasons for
this are #1 safety and #2 a cleaner cut that requires little to no filing.
Always wear safety glasses and I also use leather gloves.

72,
Jimmy,. W9JDH

Hello, Randy. I just so happen to have a copy of original. I will copy it, need to go to kinkos, and try to get it to you asap. Only need address to send to, compliments of the community. kf7yff, shawnr. On Saturday, August 17, 2019, 6:34:09 PM PDT, Randy.AB9GO <randy.ab9go@...> wrote:

Good evening,

I just acquired in oak hills research dd-1 today unfortunately without the
manual. Does anyone have a scanned copy that they could send me?

Thanks,
Randy.ab9go

That is a great tip James !
Jim WB4ILP

Hi,

I am not mass producing anything here. I use Wiss aircraft snips that resemble extreme heavy-duty "scissors'. Scribe your cut lines and use reasonable care (required of for tools).

73,

Bill KU8H

--
bark less - wag more

I use a table saw. If the metal is thin, sandwich it between a couple of plywood scraps.

Quadrature mixing to baseband is highly in vogue. The imprecision of the 90 degree mixing is corrected after a/d conversion by digital processing. I am thinking the kx2 does this. The qcx in contrast using resistive tweaking to cancel its image. The built in routine to make this adjustment is amazing.

73 curt

Good evening,

I just acquired in oak hills research dd-1 today unfortunately without the
manual. Does anyone have a scanned copy that they could send me?

Thanks,
Randy.ab9go

I think I'll add one after the books done. We do have a firm contract now and a deadline of Jan 1. All but three of the 17 chapters are done.

Hope all is well!!
Jack, W8TEE

We use a compound saw to cut aluminium angle at the local Mens Shed.

Provided you use a proper aluminium cutting blade, it does make nice neat cuts with very little touch up of the edges needed.

Aluminum cutting blades are not necessarily fine tooth, ours has less teeth than the wood blade. It is the angle of cutting tip and offset of the teeth that are important.

Couple of proviso's:

The blade MUST be in good condition, any chipped or damaged teeth and it can grab and rip the aluminium off the table (one blade got damaged and it threw a chunk of aluminium a good distance down the shed at quite a velocity).

Wear gloves and safety glasses when doing the cutting.

--
Terry VK5tm
www.vk5tm.com ( )

Until I bought my 8" brake/shear from Harbor Freight I cut aluminum and brass on my table saw and band saw all the time. No problem except I didn't use my best blades on the table saw, and I cleaned off all the metal dust carefully. Even with a fine tooth blade, it takes a little work with a file. I find file work an enjoyable and relaxing skill, but not everyone does. I still cut aluminum and brass with the band saw if it's too thick for the shear. I think the limit on the shear is around 0.050". Occasionally, I make enclosures from 0.090.

When I'm making a base for a bug, I cut 1/2" thick brass with the band saw. It needs to be fed slow and requires frequent pauses to let the blade cool. Easier than a hacksaw, but not necessarily faster.

A hacksaw does a fine job for panels too, if you don't mind some filing to get it perfect.

I think the Harbor Freight brake/shear is going to be in my will. One of the BEST tool investments I ever made for this hobby.

Eric KE6US

I hope to get a shear soon but what about using a table saw, radial arm saw
or bandsaw for sheet aluminum. I have all three of these in my shop.
There are some videos on YouTube.
Comments or suggestions?
Jim WB4ILP

If I would have read the first line I would have known that it is for 40 meters. Oops

Nice job Jack, what band is it for and I am surprised that you don't have a frequency display

What I was interested in was that it contained both the DDS and the QSD.

I do have Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"a couple of the QRP Labs SI-5351 modules and I
am planning on buying his receiver module and the phaseshift networks.

I've built a few filter using SMD caps mostly 0802 and 0603 size with excellent results.
The main advantage I found was the parts were typically 5% marked and tested closer.
So the calculated values and the as built values tended to be much closer. That and
they were way cheaper for a potload.

That and they are also much better for RF in general.

Allison
--
Please reply on the group, no private emails we as a group get to share info that way.

Bob

Maybe that's a bit high end for an HF application. That board may require a more expensive fpga board to control it.

DDS was the rage in qrp for a while, now there are much cheaper silicon chips with 3 PLLs. Look around qrp-labs website. Others provide similar stuff. As all this stuff is fine pitch surface mount, many purchase assemled boards, at least for those parts. When the QSX transceiver kit finally hits the market it will be the rage. With what little spectrum is propagating these days, a single band qcx or most anything else is a nice ride.

Curt

Against that, they have less stray inductance because of the lack of
component leads. Back in the days when SMD parts were shiny and new,
their first widespread use was in UHF and microwave circuits for that
reason. At the time they cost more than through-hole parts and robotic
assembly was not yet a thing, so they were chosen solely for
performance.

Thanks Mike,

I have used them for LPF and BPF designs with no problems but wasn't sure about using them in Crystal filters. I also am using size 1206 caps and think I will give it a try and then sweep it to see if it has any effect on the calculated filter. I have read about ground capacitance when using SMD caps with them being so close to the ground plane but haven't really seen any real problems at HF frequencies.

Joel
N6ALT

Hi Joel,

I prototyped crystal filters with through hole capacitors, then made the actual PCB with 1206 SMD parts. Seems to work just fine and reproduces the bandpass characteristics of the prototype. I didn't do proper measurements, but it is "good enough" for my use, FT8 monitoring receiver. As other people mentioned, the biggest impact on the filter characteristics is from the crystal frequency matching and the load impedance matching. Capacitor tolerance and losses are down the list of factors.

73, Mike AF7KR

Hi all,

Just wondering how people feel about using SMD caps when building SSB/CW crystal filters as opposed to other types of caps. I have used them all, just curious.

Joel
N6ALT