Recent Posts

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21
Manuals / Re: Mfj9406
« Last post by The Radio Shop on October 18, 2020, 07:04:53 AM »
22
Electronic Video Blog / Re: #79 Eico Model 147A Repair and Test
« Last post by The Radio Shop on October 18, 2020, 07:03:18 AM »
You can use either.
I get my caps from Just Radio
23
Electronic Video Blog / Re: #79 Eico Model 147A Repair and Test
« Last post by mrkeetz on October 15, 2020, 10:24:28 AM »
Hi folks. I know this is an older post, but I found the video very interesting. I recently dug my Eico 147 out and dusted it off. Plugged it in, and immediately got the bad hum. Trying to source the filter caps, I noticed a huge difference between prices with radial and axial caps. Am I missing something? Would I be able to get away with just using radials?

Any help is greatly appreciated.
24
Home Brew And Tech Forum / Re: The Pine Board Project (Metal Chassis Version)
« Last post by The Radio Shop on August 31, 2020, 07:22:04 PM »
Thanks,
I could not stand seeing that scratch. So removed the front panel, sanded and repainted it.
25
Home Brew And Tech Forum / Re: The Pine Board Project (Metal Chassis Version)
« Last post by Toolmanchris on August 30, 2020, 05:57:55 PM »
Nice work as usual. Shame about the scratch though, been there and done that many times  :)
26
Electronic Video Blog / Re: #118 Yaesu FT-2800M No Power On Repair
« Last post by The Radio Shop on August 22, 2020, 07:08:00 PM »
That sounds like the RF final amplifier transistor is out.
This is a RF module. Sometimes the ceramic substrate cracks.  You can remove it, take the plastic case off and see if you can see a crack.

Have a look at this page for an example.
https://www.rftechnology.com.au/downloads/EB0405.pdf
27
Electronic Video Blog / Re: #118 Yaesu FT-2800M No Power On Repair
« Last post by Jnagle81 on August 22, 2020, 03:03:04 PM »
I just aquired a yaesu ft-5100 and it has low output on vfh <1w. Do you have any videos on this unit or have any resources for it. Thanks
28
Power supply has started. I decided to go with solid state. This is because the extra voltage is needed for more power out of the transmitter.
29
Started the power supply.

First thing I did was build the tube rectified circuit on the breadboard. We ended up with about 190 volts on the B+.
Now we know the transformer is 250 volts but this is what happens when you use tube rectification.

EDIT TO ADD PICTURES


I then built up a solid state  circuit.  But this time we get 390 volts on the B+ and a tap for the preamp at 190 volts.
Remember this is unloaded. No load on the supply.

EDIT TO ADD PICTURES
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