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Author Topic: relay substitute  (Read 1850 times)

Offline partee

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relay substitute
« on: September 07, 2022, 0826 UTC »
Hi everyone,

I'm new to RF and electronics in general.  I'm want to build a Fireball transmitter as described in the 11/90 issue of 73 magazine.  One of the parts is a relay from Radio Shack (RS 275-243).  It's no longer sold.  Does anyone know of a replacement?  Thanks for any help.

Offline Brian

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Re: relay substitute
« Reply #1 on: September 07, 2022, 1853 UTC »

Offline Stretchyman

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Re: relay substitute
« Reply #2 on: September 07, 2022, 2015 UTC »
Any 5V relay would work. I wonder what you intend to do with it?

Str.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline partee

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Offline partee

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Re: relay substitute
« Reply #4 on: September 08, 2022, 0209 UTC »
Any 5V relay would work. I wonder what you intend to do with it?

Str.

I want to make a Fireball transmitter

https://imgur.com/a/vbvoDvB


Offline Stretchyman

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Re: relay substitute
« Reply #5 on: September 08, 2022, 1302 UTC »
What do you intend to do with the transmitter?

Oh, it doesn't look much if a fireball at all.
I guess it is tongue in cheek!

I don't get it?

Turn an oscillator on and off?

Is that it??

Str
« Last Edit: September 08, 2022, 1427 UTC by Stretchyman »
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline Charlie_Dont_Surf

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Re: relay substitute
« Reply #6 on: September 08, 2022, 1756 UTC »
Oh, it doesn't look much if a fireball at all.

We can fix that.

If he runs enough RF power to burn or weld the relay contacts and then hot switches the relay, then he might just be able to make an actual fireball. (This would require quite a bit more RF power than the 40 milliWatts listed on the schematic.)
I don't STRETCH the truth.

"Every minute I spend in this room, my signal gets weaker.
Every minute Charlie squats in the bush, his signal gets stronger."

Offline Stretchyman

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Re: relay substitute
« Reply #7 on: September 09, 2022, 0721 UTC »
Yes, I'm concerned the author is under the impression the circuit will offer any meaningful function.
The first radio circuit I ever made was a spark gap transmitter, that worked very well and transmitted on every frequency!

Str.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline Pigmeat

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Re: relay substitute
« Reply #8 on: September 09, 2022, 2321 UTC »
`73 once published a detailed schematic of a spark gap transmitter. At the end of the article there was a warning you didn't want to put it on the air. They had another interesting one when fluorescent light bulbs hit the market and they found out the things oscillated at lower end of 80 meters. A complete schematic for a QRP CW rig using one, with the warning "for experienced operators only" at the end. You had to love Wayne Green.

However, the propagation charts by Tomas Hood were dead on.

Anyone want to buy some colloidal silver?

Offline Pigmeat

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Re: relay substitute
« Reply #9 on: October 06, 2022, 1436 UTC »
The Fireball, if my memory isn't completely gone, was a QRP CW rig from the 1990's. There were kits for sale and variations on it. It was along the lines of the "Pixie" and the "Talking Pixie". Now behave yourselves or I'll have to set Fansome's ghost loose on you.

 

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