Mounting the display without screws showing on front panel

Mike WB8VGE claims, “mounting any LCD on a front panel is a pain”.  Probably most constructors would agree. Here’s how Mike does it without drilling holes in the corners to hold the display.

After you have painstakingly cut and filed the panel to allow the display to fit, fasten four .250 aluminum standoffs, one on each corner, and tighten with the correct screw. Use the shortest screw you have.
Check fitment and if necessary file away any panel material that might interfere with the display.
Using a sharpie pen, mark the corners. Don’t worry about being accurate, just a general location of each standoff will be enough.
Remove the display.
Use a bastard file and scratch around the area you just marked. The idea is to rough up the material.
Now, mix up a small batch of JB Weld.
Apply a generous amount to the bottom of each standoff, trying not to fill the hole up. (that’s why it’s best to use short screws so you don’t epoxy the screw in!)
Mount the display and with clamps, clamp the display onto the panel. I use small Irwin clamps and wood paint stirring sticks.
Wait 24 hours.
Whoa! You’ve mounted the display without trying to locate the mounting holes and without drilling holes!
Unless you go in there with a channel locks, you’re not going to be able to break the bond between the epoxy and the aluminum.

Tom  AB7WT has also tried this out.  He used shorter standoffs and put the JB weld on screws instead of longer standoffs. This way he could still unscrew the standoffs. It worked well and the screws were solid. The display and bezel look nice.

Reference

Another nice build: N8GGI’s uBITx

This is a rather nice µBITx build from Dennis N8GGI.

Dennis says, “Finished wiring up the UBITX today and downloaded the KD8CEC firmware. I took my time with the case. Old retired industrial designers still like to design (and build).

“I added a keyer circuit which has a speed pot…I don’t like to run through menus to match someone’s speed. I also added a Hi-per-Mite audio filter which really makes it a nice CW rig.

“First 40 meter CW contact was New Hampshire from my QTH on Lake Erie in north central Ohio.  Second 20 Meter CW QSO was from Portugal getting a 559 report using a tri-bander at 60 feet. I tried 20 meter SSB and worked the gulf coast of Florida with a 5×6 report. It’s a great little radio! Now I still have to tackle the TX pop and try to tame down the sidetone volume issue. I hope the 1,500 watt linear doesn’t get lonesome from lack of use.”

And what lies beneath the paint!   The “see-through” version!  Dennis says, “Kinda looks like the old ‘visible V-8’ from the ’70s.”

Drive control – 2 methods

Bill K9HZ who we have already reported had developed a relay control system driven by the Low Pass Filter I/O lines.  In addition, Glenn VK3PE has also come up with a circuit that could be adapted using a digital potentiometer module to be driven by the Raduino using a digital I/O line.

Relay drive control

Bill K9HZ has now drawn up the circuit he used to allow for relay switching of drive levels by band grouping, driven by the LPF band grouping I/O lines of the Raduino.  No firmware mod is required to deliver even drive power across all of the bands.

RV1 in the yellow circle is the existing drive pot in the uBITx.  Remove it and connect the wires from the relay as shown.  Q17C, Q18C, and Q19C references connect to the transistor Q17, Q18, and Q19 collectors.  Then set RV1A, RV1B,  RV1C  and RV1D on the basis of the appropriate band grouping selected to keep the power out flat.

 

Digital drive control

Glenn VK3PE has come up with an old circuit that could be used to work with a digital potentiometer module to use as adrive control set by the NANO  firmware on a band by band basis.

The original drive control, RV1, would need to be removed and a few parts added, along with a digital pot (I2C control) in place of R3 below to form an attenuator in the RF path.

With some careful work it should be possible to design a small PCB that fits into the holes vacated by RV1, either vertically or horizontally.

The schematic is from page 62 of the book by Randy L. Henerson on designing a Transveiver. Its a very old book (1997) ISBN 0-07-028263-3

reference

Additional PCBs for Sunil’s Case


Sunil VU3SUA  is providing extra PCBs with his uBitx case.

See http://amateurradiokits.in to purchase the case and PCBs.

1. Encoder PCB
This pcb will save you from the clutter of wiring up the encoder.

2. USB.D9. PCB
Use this board if you wish to. if you do not want to use this board then cut a small plexi glass sheet and close the open area.

3.Power Connector PCB
The DC Power supply connections are easy to install with a board to assist. The On/Off switch, Fuse, IN4007 diode and power connector are mounted on a small board again removing wiring clutter.

Care has to be taken in mounting the On/Off switch, as excessive use of soldering heat or bending of the pins on the switch may damage it.

Sunil says that he will be making further improvements in the µBITx products to make it easier to wire in kit components into the case.

 

An FT8 black beauty

Bill KC5SB has been using his “black beauty” µBITx on the FT8 digital mode and has already worked a station in Brazil with no problems.  Bill has installed a fan because he spends a lot of time on digital modes. The display has been replaced with one with a blue background (goes better with black) and the unlabelled switch on the back is for the fan – high, off, low.

The case can be purchased here.  It has, of course, been painted.

Reference

A 5v bus for the uBITx

Nigel G4ZAL has  just finished his µBITx build and modded it a little in readiness for adding additional boards/hacks.

He cut the track feeding the TDA2822 and fed it with 5v from a little Radio Control UBEC.  At the same time, he removed the 5v regulator on the Raduino and fed that from the UBEC as well.   You can see from the photos that he has added a little ‘bus’ for picking off further 5v supplies as required.

His installation looks pretty snappy in the well used Banggood case

 

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And the µBITx is already hard at work on 40m using the FT8 digital mode:

Reference

Another nice build – we do like the speaker grill!

Nelson KG7GYS has built his µBITx into “a box I had bought for some project over a decade ago and never got around to using”.

He ordered a speaker grill from Amazon for about US$2.50. He decided, like many of us, to use a pot with switch from his junk box in order to have a standard size shaft (it came out of an old Radio Shack CB set).  The knobs are from an old Henry Tempo One (Yaesu FT-200). The speaker is from his junk box, as is the 12vdc fan.

We all want to know what the heck all that test gear does!

Reference

A 3.5″ screen for digital modes/ rig control on the front panel

Vince, N2AIE,  worked Tom VE3THR and Bill NG1P tonight on 7.277 out of his QTH in Cedar Rapids IA.  These were his first uBitx contacts with other uBitx and bitx40 rigs.

Vince has loaded (after some angst) the KD8CEC firmware, and has the rig interfaced with Ham Radio Deluxe (in both directions).  His rig also has a 3.5in touchscreen Raspberry pi for digital modes built in on the right hand side of the front panel as illustrated above.

Take a look at the rear panel of his rather attractive build:

700Hz CW Audio filter board

Nik VK4PLN has yet another board design – this time for an audio CW filter similar to the QCX and HiPerMite.  Nik says “he is  loving the cheap and easy EasyEDA/JLPCB boards and simple web designer”.

He “takes no credit for the design, just copied it and added a switching relay.   He has ordered 10 boards at $10 posted”.

Details of the filter

Center Frequency: 700 Hz
Bandwidth: 200 Hz
DC Power: 5VDC
GAIN: Upto 20dB via R11 and R12 + trimpot.

Resistors 1206 SMD:
R1 33k
R2 33k
R3 1M
R4 47k
R5 47k
R6 36k
R7 36k
R8 10k
R9 750k
R10 10
R11 100K
R12 100K

Capacitors 1206 SMD:
C1 0.1u 104
C2 47n 473
C3 36n 363 (33n + 3n3 mount on side together)
C4 1n 102
C5 39n 393 (33n + 5n8 mount on side together)
C6 1n 102
C7 2n2 222
C8 2n2 222
C11 0.1u 104
C14 220u Electrolytic

Other:
IC TLC274
Relay OMRON G6S-2-DC5
200K/100k trimpot

R11 and R12 are optional to parallel the 200k trimpot to make it a logarithmic 100k.   Or just use a linear 100k pot.

Use a switch connected to 5V to turn on the filter.

This powers the opamp and switches the relay feeding the audio into the circuit.  When off the relay just passes the audio straight through unfiltered.

Reference