What's on your Workbench?

[VK3ALB]

...I print onto Avery crystal clear laser shipping and parcel labels (1 per A4 sheet)

Peter, have you tried it with a colour printer to see if you can do coloured meter scales like this?

Bert
VK3TU

Wow Bert, great job. What program did you use to make that?

Sent from my SM-G900I using Tapatalk

[VK3QI]

Bert,

I haven't tried colours on the laser printer, but I am certain it would work OK. The trick is to (1) choose bold for the printing and (2) make sure the laser printer is set for the correct label sheets - there is actually a software code for the particular sheets which most big name laser printers will recognise.

Cheers


Peter VK3QI

[VK3TU]

Wow Bert, great job. What program did you use to make that?

Sent from my SM-G900I using Tapatalk

I used Galva by F5BU. A pernickety bit of software to use, but it produces some great results. I can't recall who put me onto it...might have been someone down at the GARC.

Bert

[VK3QI]

Bert,

I did a quick mock-up of your meter dial on Word to fit on an A4 sheet of clear label film.

Attached is a quick snapshot of the finished product. A little bit of red colour loss on parts of the print but that is overcome when you do a practice run through on plain paper to stir up the toners!

It certainly works! With shopping around I can usually get 25 A4 sheets for around $45,which makes it a relatively cheap and easy method of producing stick on panels.

Cheers

Peter VK3QI

[VK3QI]

Bert,

Only out of focus because of my bad photography - attached a better one with a white background.

Cheers

Peter VK3QI

[VK3TU]

Looks good Peter. Some of the paper scales I've done for other jobs in the past have tended to wrinkle a little bit with changes in humidity. The idea of a polymer substrate attracts me because it should prove more stable in the longer term. I'll chase up some of those labels.

OK on the red loss too. I know I had to do several print runs to get a suitable print when I made the original scale on white paper. Sometimes the printer can be as pernickety as Galva. One technique I've used in the past is to save the image and resample/resize it using Irfanview. Sometimes, it can help increase the print density for solid colours.

Thanks.

Bert
VK3TU

[VK3QI]

Yes Bert,

I would do the same thing with Irfanview or other similar program - up the contrast and colour saturation for example.

Cheers

Peter VK3QI

[VK3ALB]

Following on from my rotator controller project I'm also preparing the new mast arrangement for field day. By putting the rotator at the base of the mast the amount of effort required to lift the mast into the air is minimal. With careful planning an arrangement like this can be raised by one person.

A hinged base plate makes it easy to bring the mast to a vertical position.

Foam noodles limit injury should you run into a guy.

[VK3JUG]

i like the pool noodles what a great idea. I'm always looking for tape streamers or shopping bags to alert people of my trip hazards, and i've even got spare noodles in the shed! Thanks for the tip Lou.

[VK3ALB]

i like the pool noodles what a great idea. I'm always looking for tape streamers or shopping bags to alert people of my trip hazards, and i've even got spare noodles in the shed! Thanks for the tip Lou.

Thanks Peter. It's a bit difficult to slide them over the guy tensioner so I split them to make it easy to install them. Doesn't solve the trip hazard but hopefully reduces it significantly.

[VK5TX]

Printed up some mounts for a 400mm dish to take a WR-90 feed

[VK4REX]

Had an interesting fault with my FT817. It kept coming up in dual watch mode, antenna always to the front connector, SSB step size at 2.5Khz, MTR to ALC and showing the FST button had been pressed. Every thing else was working normally. Going into the menu's and setting everything as I wanted it the radio then performed flawlessly until switching off. Then it went back to the incorrect settings.

I figured it had to be the EEProm or the I2C buss to the EEProm, seeing as other storred functions were being saved eg screen color I figured the I2C buss must be ok along with the pullup resistors.

This led to the EEProm being faulty at some locations, looking up the memory map for the prom it confirmed the locations for all the functions that were failing were in adjacent sets of cells.

I copied the calibration constants, removed the EEProm (Q4006 on the right hand side of the pcb layout) and replaced it with a AT24C64D-SSHM-B from RS components (stock number 7380072). Only 90c each but you have to buy 10. The original eeprom is speced to work from 1.8v hence the one I chose meets that requirement - had to come from the UK of course.

On powering up the radio it seemed like it was going to fail but the microprocessor was storing default values in the EEProm to get things started. Went back to the "secret menu" and put in the previously copied calibration constants and the radio worked flawlessly.

A work of warning, the location of the EEProm is on the front side of the front panel. The tracks are very fine and I would only recommend removing the prom with hot air desoldering equipment.
BTW for those not aware - to remove the rotary encoder you slip off the rubber covering the tuning knob and there is a hex nut under the cover that holds the knob on.

Hope this may help others.

[VK3ALB]

Had an interesting fault with my FT817. It kept coming up in dual watch mode, antenna always to the front connector, SSB step size at 2.5Khz, MTR to ALC and showing the FST button had been pressed. Every thing else was working normally. Going into the menu's and setting everything as I wanted it the radio then performed flawlessly until switching off. Then it went back to the incorrect settings.

I figured it had to be the EEProm or the I2C buss to the EEProm, seeing as other storred functions were being saved eg screen color I figured the I2C buss must be ok along with the pullup resistors.

This led to the EEProm being faulty at some locations, looking up the memory map for the prom it confirmed the locations for all the functions that were failing were in adjacent sets of cells.

I copied the calibration constants, removed the EEProm (Q4006 on the right hand side of the pcb layout) and replaced it with a AT24C64D-SSHM-B from RS components (stock number 7380072). Only 90c each but you have to buy 10. The original eeprom is speced to work from 1.8v hence the one I chose meets that requirement - had to come from the UK of course.

On powering up the radio it seemed like it was going to fail but the microprocessor was storing default values in the EEProm to get things started. Went back to the "secret menu" and put in the previously copied calibration constants and the radio worked flawlessly.

A work of warning, the location of the EEProm is on the front side of the front panel. The tracks are very fine and I would only recommend removing the prom with hot air desoldering equipment.
BTW for those not aware - to remove the rotary encoder you slip off the rubber covering the tuning knob and there is a hex nut under the cover that holds the knob on.

Hope this may help others.

Interesting fault Rex. Do you think it was a case of too many writes of specific values or just one of those things?

[VK4REX]

Hi Lou

Interesting question. The particular 817 I bought in 2004 so it's 12 years old but not a lot of use, the odd contacts from Nauru and Manus Island where I worked with the US Gov and a bit more use from 2013 when I got back into microwave activity.

My guess it it just suffered a premature failure as the number of writes from the data sheet would far exceed what I might have done. Yaesu actually don't write the frequency to the prom until you change band or turn off to minimise writes.

I guess we could start to see similiar faults appearing in the older radios from now on.

Rex

[VK4REX]

Hi Lou

Been doing some more investigation into this issue.

EEProms do have limit as I have found out. The memory capacity is dependent on 2 things, temperature and voltage. A high temperature and a high voltage will limit the memory retention of the device. The EEProm in the FT817 operates at 5 volts and we tend to use them in moderately high temperature environments (except in VK3). Low temperature and voltage improves their memory retention.

I found an excellent article from Microchip showing the effects of these 2 variables together with a calculator to show the expected failure rate and it's nothing like the 1 million write cycles shown on the data sheets.

https://www.google.com.au/url?sa=t&rct= ... Go&cad=rja

I realise some of this is marketing but it gives an idea of the problem and the potential future failure rates we may expect in 817's or anything else with an EEProm. Has been an excellent exercise.

Rex

[VK3ALB]

Hi Rex,

Interesting indeed. I never considered there could be a difference between write modes to the device. I guess we all have something to look forward to.

I can picture John Cleese walking into a repair shop complaining his radio doesn't work. Behind the counter Michael Palin inquires, "You, haven't been using it have you"?

Thanks for sharing.

[VK3YE]

Strange sound effects possible with SDRs, wireless microphones and drone machines (the non-flying variety).

https://www.youtube.com/watch?v=N47uxPTGoIc

[VK5ZD]

LO for my next 47GHz transverter.
ADF4351 PLL board $33.30
Arduino Mini $2.50
Minikits multiplier $32.50
The piece of Vero board has some resistors to reduce the 5v levels on the Arduino to 3v for the PLL board (divider using 220 and 330 ohm resistors).
There's a switch (not visible in the photo) which changes the PLL output between 3,912MHz (144MHz I.F.) and 3,911.9166667MHz (145MHz I.F.).
The output from the multiplier is either 11,736MHz or 11735.75MHz at -2dbm so I'll need to add an amplifier to bring the level up to about 13dbm.
The transverter (Kuhne MKU 47 G2) multiplies this by 4 to get the final LO frequency of 46,944MHz or 46,943MHz.
I haven't used C in years so writing the code was a minor challenge. I had an issue with variable scope which had me pulling out what little hair I have left plus I'd keep forgetting the ; at the end of each line .
However, it's now all working.

[VK3MAT]

That's very cool,

I paid 35 for mine. I have been playing with some arduino code I found on the internet but it would be nice to have a simpler version. The code is buy f6kbf. Since my code skills are still hello world it will be a struggle but I'd eventually like to end up getting rid of the screen from the code and have a few pins that I can send some logic to to adjust the freq eg for offset on 23cm for repeaters or for a 2 banded transverter. If you don't mind could you please post your code for some inspiration?

Matt

Sent from my MotoG3 using Tapatalk

[VK3AUU]

I recently acquired a 432 MHz amplifier with a single 4CX250B, originally built by VK3ZL. It is generally well constructed, bu the power transformer is hopelessly inadequate. It has 550 volt a side output with a bridge rectifier system which produces 1500 volts DC on standby, but that drops to 1350 volts with the tube drawing 100 mA standing current. This drops further to something around 1000 volts at 300 mA. Maximum power out is around 100 watts before the screen current goes negative. I have an adquate transformer which I will have to place outbouard as there isn't room in the box. This will produce the required 2200 volts under load.
One other problem seems to be that the input line is a bit short so that it is somewhat high in frequency, but it takes drive at 432.2 MHz. As I have plenty of drive available, this is not a problem and if necessary I can make an external matching unit to get the VSWR on the driver down to an acceptable level.
If I get it all sorted I will have to build a decent antenna, and have a go at some more EME from my hole in the ground. Stay tuned.

David
VK3AUU