Radio Holder

[Jack Crow]

Im back,
Duck and cover.

I have posted about this project before, so this is a follow on / addition.

Was playing with an idea.
Some time back I was asked to make a 19 inch rack panel.
That works out to over 453 mm on a 150mm printer.

Had to print on the diagonal after breaking the design up into three sections that slot together.

Learning curve was steep but now I can make these panels w/o too much stress.
Im beginning to think of it as Lego for ham radio.
With these panels, I can snap the parts I need together and change the nature of the product.

This is yesterdays print.
This falls short of my 97% rule, but it's a good data point on the learning curve.

This design has issues and points towards improvements.

The project involved mounting a cheap Chinese dual band radio into one of these panel segments.

The QYT8900R radio is small and has enough transmit power to be useful.
Think of it as a 20 watt vhf HT that is hard to program.

This panel is the first project I have in mind using this radio.

Will share some of the things that worked and items that failed.

Bits of this one curled up at the extremities.
Going to try again after some mods, with different plastic that has less tendency to warp and see if that fixes the issue.
Worst case I can break this up into smaller segments and bolt them together.

That microphone hook has to move, it just gets in the way.
Want to move the nose of the radio forward a little bit.
So people can see the Make / Model number on the top.
May want to make a companion panel with an external speaker, this thing is going to deaden the sound, no two ways about it.

10-21-2017 001.JPG

Also some of the locations need tweaking.
See how the radio is in a slightly 'nose down' configuration?
That can be fixed easy enough.
A Z change someplace.
Also made use of the OEM punched steel mounting bracket.
This gives the print a bit more rigidity, and improves heat sinking in the radio slightly.
Small radios in service get hot, it's a fact of their construction.
Every little bit of metal surface helps.

I did not add a 'bottom' photo.
That was an embarrassment.
Failed to line up the screw slots to the plastic, had to drill some holes in the printed part to hold it all in place.
That will change.

10-21-2017 003.JPG

The last one is the 'Rear View'.
This is to show the depth relationship.
I laid it out with the bottom level to where the mounting bracket ends. No need to go further.
It also is home to a large opening under the bracket to save a little on filament, that actually worked good.

10-21-2017 004.JPG

Couple of tweaks and it will be good.
Going to change to a more stable plastic that should not bend up so bad.

This is my excuse and Im sticking with it.

Be well all
Jack Crow aka Radio Mike in Virginia Beach

[Jack Crow]

Hi all,
Passed the my 97% test, so now it's good enough to use.

10-22-2017 007.JPG

As you can see I used one of the GM style dash speakers.
3.5 inch with a heavy magnet.

Small operational note.
The jack space for the external speaker would not allow the soft plastic of the 3.5mm connector to seat properly.
Had to use a sanding drum on the Dremmel tool to take down some of that edge so it would into the space provided inside the radio.

10-22-2017 010.JPG

With a good speaker you can get some good sound + volume out of these things.

The project will be finished when I add one more panel to the assembly.
It is going into a portable equipment case as part of a 19 inch rack.
That case holds communications gear for emergency situations that amateur radio operators help out in.

Hopefully you as citizizens and civilians never have to evacuate due to weather or some kind of disaster.
It's a tough thing to experience.

In shelters and emergency managment HQ, the background noise runs the range from operating room quiet or simply bedlam.
You never know what your asked to respond to.

High quality and loud audio is a requirement.
So a strong speaker with good power handling ability is essential.

This is a very good speaker.
It adapts well from the auto sound roll to the communications roll.

The panel is 20mm thick.
Printed at 20% fill density.
That is more than solid enough for good sound reproduction.

10-22-2017 012.JPG

This gives the over view.
If you look close you might be able to see the grill for the dinky 35mm speaker built into the radio.
The new one is 86mm by 35mm deep. Packs the same mass as the radio it's self.
Top view
10-22-2017 017.JPG

When I think of something else to put in a rack panel photo, will put some photos up.

Be well all.
Jack Crow aka Radio Mike in Virginia Beach

[RetireeJay]

I must say I'm surprised at the antique coaxial connector used on that radio. Those "UHF" connectors were known to have uneven impedance back in the 1960's, almost 60 years ago! They're also hard to assemble (although there are many variants for different styles of coax). I see you're using a "connector tree" to get to a reasonable connector for your actual antenna cable.

[Jack Crow]

RJ
SO239's passes for the standard. Not much has changed.

Had my share of good and poor ones.

Burned my self silly once with the output of a UHF repeater and what turned out to be a lossy barrel connector.
It did get very hot. Sizzle finger tips hot.

Things are better now. Better plastics. Things work at higher frequencies.
Silver vs Chrome plate.
What works at CB may not play nice at UHF.
RF loss is a bi directional street.
If they make a radio with an expected sensitivity, part of that check is to make sure the antenna jacks are not lossy.

One of my buds used to design wifi type antennas. His standard check for loss in the ray dome plastic was to microwave a sample.
It it got hot, it was bad.
Absorbed at near the frequency the 802.11 radio was going to work at.

The RT Angle connector is so that I don't stress the RF cable on my bench if I tip the thing back to examine the bottom.

Hope your well, not much new to report.
Jack Crow aka Radio Mike in Virginia Beach