Re: UHF Range: Partial RX/TX Issue.
The current drawn from the power supply is also a good indicator, ideal current on UHF TX on min RF is aroubd 2.5 Amps, at 50 Watts expect 12-15 Amps on FM or CW. PA is around 50 % efficient.
Most
By
Andrew Lenton
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#647
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Re: UHF Range: Partial RX/TX Issue.
For that radio, I found the best SWR/Wattmeter would be the Daiwa CN-801 which covers 140-525 Mhz, Full scale, 200 watts.
Bill
K2WH
Sent: Sunday, September 04, 2022 9:35 PM
To:
By
Bill
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#646
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Re: UHF Range: Partial RX/TX Issue.
Richard.
Have a look at http://www.g1ivg.com/ft847.htm for jumper settings.
Depending what your band plan is, it is easy to see what the radio will TX
from his listing.
You have suggested links fitted
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Andy Bosworth
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#645
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Re: UHF Range: Partial RX/TX Issue.
Check the DC switching voltages toggle as you change frequency this will give a clue if the logic is switching correctly
73
Andrew
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By
Andrew Lenton
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#644
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Re: UHF Range: Partial RX/TX Issue.
Sounds like you are making progress you will get there, the pin diode mod does bring down the noise very noticeable.
You also need a 50 Watt dummy load to go with your srw meter
BR
Andrew
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By
Andrew Lenton
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#643
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Re: UHF Range: Partial RX/TX Issue.
Bill K2WH-> Hi Bill, I only just discovered the inability to enable the Alaska emergency frequency during a complete functionality check of the radio.? I went thru all the settings to see what was &
By
Richard
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#642
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Re: UHF Range: Partial RX/TX Issue.
Check this section. it shows the cutoff for each frequency you mention and
I believe this is where you need to start to conduct some tests..
[image: FT847 unwell on
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Spence G5STO
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#641
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Re: UHF Range: Partial RX/TX Issue.
Just chucking this out there but surely the signal passes through the 70cm BPF? If anything in the 70cm BPF has come adrift then the radio will have a broken signal path. Is it possible soon as you go
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Spence G5STO
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#640
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Re: UHF Range: Partial RX/TX Issue.
Many years ago, I had an 847 and the previous owner modded it and it virtually transmitted anywhere.
However, I do not think it would go beyond 512 mhz, xmit or receive.
Of course, this was
By
Bill
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#639
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Re: UHF Range: Partial RX/TX Issue.
I have further read this, and it makes no sense, it seems you have a corruption, or an illegal settings near the CPU
Check this site and let me know what you find:
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Andrew Lenton
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#638
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Re: UHF Range: Partial RX/TX Issue.
My goodness this is an interesting fault, how much power do you get at 460MHz and akso6at the lower frequencies it does transmit at?
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By
Andrew Lenton
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#637
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UHF Range: Partial RX/TX Issue.
Hi all, I have a rather strange issue with my '847 that I haven't yet figured out the cause for: It doesn't receive or transmit between 420 MHz and 459..9995 MHz.
Background info: I'm 3rd owner of my
By
Richard
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#636
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Re: MH-36D Microphone puzzle
Hi Max,
So, you're connecting the mike ground pin to the chassis through the
connector shell?
Chassis ground should be the same as pin 5, no? They're separated
now,
By
Greg D
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#635
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Re: MH-36D Microphone puzzle
Hi Greg,
Not sure if you have tried this but it has worked for me in the past.
Take the mic connector apart and solder a bare 2" or so length of wire to pin 7. Route the other end of the wire back
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Max Donoghue <ve3tmt@...>
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#634
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Re: MH-36D Microphone puzzle
A quick update...
I'm now thinking the problem has nothing to do with C104.? I tried inserting a capacitor in series with the mike line (pin 8 on the round connector), and the problem remains
By
Greg D
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#633
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Re: MH-36D Microphone puzzle
Hi Andrew,
Looking at the schematic (if this is correct:
https://www.tinymicros.com/mediawiki/images/9/9e/Yaesu_MH-36_Schematic.pdf),
I don't see one. Where would it be?
By
Greg D
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#632
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Re: MH-36D Microphone puzzle
Right, pin 8 is mike, and pins 5 & 7 are the grounds.
So, leaving pin 5 unconnected seems to have helped a bit, but there's still a hum.? After some troubleshooting on the local repeater, we noticed
By
Greg D
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#631
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Re: MH-36D Microphone puzzle
Make sure there is a 560 ohm resistor across the mic!
BR
Andrew
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By
Andrew Lenton
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#630
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Re: MH-36D Microphone puzzle
I think you have the mic wired wrong. Pin-8 is the mic input not ground, which would explain the hum. Also, do not tie the mic ground (Pin-7) and the "other" ground (Pin-5) together. They are
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Omni
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#629
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MH-36D Microphone puzzle
Hi folks,
I've been using an MH1-B8 microphone for a while (few years), substituting for the rig's original MH-36D which had the disintegrating rubber cord problem.? Following up on recent
By
Greg D
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#628
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