Kuhne QH40A crystal heater problem
I tried the QH40A crystal heater mod as presented all over the internet. However, it did not work out for me ( my FT847 is a 2004 model).
I can't quite figure out how it is possible that for some people this mod actually DOES work.
The FT847 is using a reference crystal especially cut to be stable at or around room temperature (25C).?
What you actualy do with the QH40A crystal heater is bringing your crystal to a very stable 40 degrees, a temperature on which the FT847 crystal itself is ...unstable.
What you gain (at best) is...nothing.
On the contrary, with the QH40A installed, the frequency on my FT847 is continuously increasing at a 1Hz per minute rate (on 144Mhz)? for hours on end.
Without the mod, at least it more or less stabilize after a while.
Crystals to be used in an oven are cut very differently.
|
In message <a12210a3-bdb4-4c00-5da4-23e9fe78920e@...>, Alan G3WXI aka G8AGQ <strongmra@...> writes Good Evening Brian
Brian Howie GM4DIJ wrote:
I got mine 2nd hand in the late 90s. I've just fired it up on 4m for a sked. I only really use it for 4m and 6m these days and as a 432 MHz IF for 13cm and 9cm. I do use it for general coverage receive on SW and VHF/UHF. Some day I'll get? it back onto TopBand, which is the only SW band I'm interested in.
The only faults I've had are the notorious on/off switch, the CW key socket coming loose off the board? and a 21MHz fault due to a blown band switch diode.? I did the high power capacitor? mod for 4m while I was fixing that one. I also replaced the? hard wired battery with a holder too.
Brian? GM4DIJ
I too am a long time 847 owner, having bought mine used around the change of the century from an old timer in ill health (as I am now) and I am writing to you regarding your reference to 4M conversions.? I sent my 817 to ML&S to have the Power switch replaced about 8 years ago and asked ML&S Service manager about the pros and cons of the 4M conversion, but he was not enthusiastic!
But as the years pass, I am seeing more and more instances of conversion!
I was using 4M way back on 4M PMR and a range of Microwave Modules products. Meanwhile my 4M equipment consists of a converted PMR Mobile and an Eastern European transverter but it would be nice to have 4M on my FT847!
Your comments would be appreciated!
73s - Alan S, G8AGQ/G3WXI Hello Alan, The mod I did was the removal of one capacitor C5051, PA1O's modification and the snipping of the ALC line. There are other ones,that require changing more components and one that involves putting a small ferrite core into one of the coils. I tried the latter but I wasn't happy with it in terms of improvement. I didn't add the RX preamp since the external PA I use has one. I can now get 65W out barefoot on 4m and the efficiency is much improved. 6m output is much the same. It means I can drive the external PA properly. I started out on 4m in about 1975 using a converted Murphy lowband PMR valve rig as a transverter, then a Meon plus a Pye A200, which I also used when I got the 847. The 10W was just about enough to drive it, and I needed an external rx preamp. I recently modified a 50MHz TE Systems linear to 70MHz , but found it needed about 12 to 15W to drive it. Hence the mod to the 847. I've not found a down-side to the mod. There's no sign of unwanted spurii. Someone else might want to comment. 73 Brian GM4DIJ -- Brian Howie
|
Good Evening Brian Brian Howie GM4DIJ wrote:
I got mine 2nd hand in the late 90s. I've just fired it up on 4m for a sked. I only really use it for 4m and 6m these days and as a 432 MHz IF for 13cm and 9cm. I do use it for general coverage receive on SW and VHF/UHF. Some day I'll get? it back onto TopBand, which is the only SW band I'm interested in.
The only faults I've had are the notorious on/off switch, the CW key socket coming loose off the board? and a 21MHz fault due to a blown band switch diode.? I did the high power capacitor? mod for 4m while I was fixing that one. I also replaced the? hard wired battery with a holder too.
Brian? GM4DIJ
I too am a long time 847 owner, having bought mine used around the change of the century from an old timer in ill health (as I am now) and I am writing to you regarding your reference to 4M conversions.? I sent my 817 to ML&S to have the Power switch replaced about 8 years ago and asked ML&S Service manager about the pros and cons of the 4M conversion, but he was not enthusiastic! But as the years pass, I am seeing more and more instances of conversion! I was using 4M way back on 4M PMR and a range of Microwave Modules products. Meanwhile my 4M equipment consists of a converted PMR Mobile and an Eastern European transverter but it would be nice to have 4M on my FT847! Your comments would be appreciated! 73s - Alan S, G8AGQ/G3WXI
|
Reissue of Winlink and the FT-847
Hi Folks,
On August 5, 2021 message #214 I had written the following message:
"I am having a problem originating a message.
Before I waste anyone's I would like to ask the following question of the group before proceeding.
Is there anyone who has successfully installed and can run WinLink psp? and Gateway messages without using CAT using a Yaesu FT-847?"
I received a reply from A Greg D. that I had a difficult time understanding as I am still new to Amateur Radio.
The mistake I made was not letting him know.
Worse yet after reviewing the message I noted I missed the last line he wrote:
"Or just buy a Signalink interface..."
With hat in had and apologizes I need to state that I have a SignaLink for awhile now.
I originally purchased it in order to run fldigi which works flawlessly.
The problem I am having is I originating a message using P2P and using channel selection. If someone else originates a message I can do a P2P sometimes.
It makes no difference whether I use VARA HF or ARDOP same problem. Telnet works fine.
I have since learned that a fellow Ham with the same radio and SignaLink has the same problem with fldigi working correctly.
I would like to get WinLink working so I can get involved with them. It's another tool for my Ham Radio tool box when things go belly up.
Thank You,
Steven/kc3dow
|
Ok folks, I have no idea what happened but after a reset I'm back in the group.
No need for action boss.
Leighton. GW3FSP.
|
We receive a lot of various brand radios damaged by data mode thermal runaway.
The 847 is no exception. Page 16 of the dreaded owners manual tells us that cool down time needed is longer than the transmit time applied, and suggests setting 25W max on the VHF band for extended TX times on FM and data modes.
Ft8, etc was intended to be a QRP mode with a lot of educational value
for weak signal enthusiasts, but the "all knobs full right" mentality has turned a once good M2M I heard you, you heard me bye mode. Now the primary source of IMD QRM products in and adjacent to FT8 windows is increasingly caused by stressed transmitters over configuration settings.
If you need RF power to be heard, you are better off investing in an engineered antenna system or supplemental RF power amplifier specified for the duty cycle.
Jim WA9Z
Exline Signal LLC
toggle quoted message
Show quoted text
On 12/2/2021 1:47 PM, Alan via groups.io wrote: I've? just started using my 847 on 2m FT8. What's the maximum power everyones running with 2m FT8?
|
Hi
I would stick to maximum of 25watts from 847 on 2m FT8.
I actually use 70amps from a small valve amp but i wouldn't run the 847 at full power. so stick with 25-30 watts max on 2m. The extra 2 or 3 dB is useful of course but not gonna make a load of difference .
Enjoy
73 de Rob G4UJS
|
Sorry, not thinking clearly.? Please disregard my previous.
73,
Tom K6EU
I run mine at 80-90 watts.? When running FT-8 the transmit on time is less than 50%.?
73,
Tom K6EU?
Bill the 847 will only give a max of 50w on 2m. I thought it was clear what I wanted to do with it, but let's try again. I want to run with no amp the 847 on 2m using FT8. If others are doing this between 0 and 50w max what power are you running.
|
I run mine at 80-90 watts.? When running FT-8 the transmit on time is less than 50%.?
73,
Tom K6EU?
Bill the 847 will only give a max of 50w on 2m. I thought it was clear what I wanted to do with it, but let's try again. I want to run with no amp the 847 on 2m using FT8. If others are doing this between 0 and 50w max what power are you running.
|
I run 100 watts max, that’s all I have. ? It’s been a long time since I had an FT-857, I now use the IC-9700 which is 100 watts max. ? So, since its only 50 watts, I would run full power or lower power to drive an amp. ? Many confuse the description of FT8 as a weak signal mode and it is but the term weak signal mode, describes its ability to decode very weak signals but many misinterpret this and believe they need to use low power IE. use low power. ? FT8 is capable of copying very weak signals but that does not mean you should lower your power especially on 2 meters where high power is almost mandatory if you want to work the weak ones. ? I am currently building a kilowatt amp for 2. ? K2WH ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Alan via groups.io
Sent: Thursday, December 02, 2021 3:27 PM
To: [email protected]
Subject: Re: [YaesuFT847] Power out Ft8 2m ? Bill the 847 will only give a max of 50w on 2m. I thought it was clear what I wanted to do with it, but let's try again. I want to run with no amp the 847 on 2m using FT8. If others are doing this between 0 and 50w max what power are you running. -- Bill, K2WH
|
If I recall, I think I was running around 30 watts on 2m, last time
I tried it there.? Not much by way of contacts (it was winter field
day, I think), but the 847 seemed ok with it.? I was feeding a 2x8
element CP yagi on the roof.
As has been noted, FT-8 is a weak signal mode, not necessarily a low
power mode.?
Greg? KO6TH
Alan via groups.io wrote:
toggle quoted message
Show quoted text
Bill the 847 will
only give a max of 50w on 2m. I thought it was clear what I wanted
to do with it, but let's try again. I want to run with no amp the
847 on 2m using FT8. If others are doing this between 0 and 50w
max what power are you running.
|
Alan, I would suggest you stick with 50 watts or full power on FT8. I use mostly MSK144 as I'm in a remote location and rely on Meteors or Aircraft Scatter and I use 400 to 800 watts with an 18 element beam at 60 feet.
Have fun with FT8 on 2 meters.
W7FSI DN-24 IDAHO
Bill the 847 will only give a max of 50w on 2m. I thought it was clear what I wanted to do with it, but let's try again. I want to run with no amp the 847 on 2m using FT8. If others are doing this between 0 and 50w max what power are you running.
|
Bill the 847 will only give a max of 50w on 2m. I thought it was clear what I wanted to do with it, but let's try again. I want to run with no amp the 847 on 2m using FT8. If others are doing this between 0 and 50w max what power are you running.
|
Depends on what you want to do.? I think most are running anywhere from 30-50 watts if using and amplifier.
No amp, most I would think are running full power or 100 watts.
Just my opinion.
Bill, K2WH
|
I've? just started using my 847 on 2m FT8. What's the maximum power everyones running with 2m FT8?
|
The dotted lines representing the shield of a coax cable, with the
center conductor running up the middle.? The circles are the ends of
the cable.
Greg? KO6TH
EI8KF wrote:
toggle quoted message
Show quoted text
One other
question... what do the circles attached with dotted lines
represent in the diagram??
|
Hi Mike,
Almost, and maybe.? I think.
The way I connected the Transmit Audio (externally) had the TRS
"upstream" from the DIN, with a second blocking cap in between (+ to
the TRS), and with original blocking cap upstream from there.? I had
it your way (DIN upstream), but had to swap it the other way for
some reason which escapes me right now.
But even so, I think you need to key the two jacks separately so
that the rig will route the audio to the appropriate modulator (SSB
vs FM).? I did that with an external SPDT "Packet vs FT-8" switch.?
I don't know what will happen if both interfaces are given PTT at
the same time.? Might be interesting, hopefully not exciting...
So along with the external switch, I made a patch cable between the
two jacks with the cap in-line.? The second cap is upstream from
there so the TRS's 5v PTT bias doesn't hit the audio port on the
computer (makes mine unhappy).?
I'm sure I could simplify things a bit, but with a pile of pulled
hair already littering the bench I decided to stop once I found
something that worked.? Part of the complexity was that I wanted to
do all of the modes (HF and Packet) from the variety of apps on the
Pi, and there's little consistency among them for keying the rig.?
Then I made things worse when I upgraded the Pi3B to a 4B, which is
missing the modem control signals on its internal serial port.?
Grrrr...
If you try keying both ports together, please let us know what
happens!? Where does the Transmit Audio go?
Good luck!
Greg? KO6TH
Mike - W1MI wrote:
toggle quoted message
Show quoted text
That gives me an
idea, Greg.? I wonder if I can add the blocking cap and resister
to my radio internally between the TRS and the mini-DIN and just
use the mini-DIN plug with my rigblaster plug-n-play?
73, Mike - W1MI
On Tue, Nov 16, 2021 at 07:25 PM, Greg D wrote:
I've not used the RigExpert, but have interfaced a
Raspberry Pi to the 847.? The diagram looks good, at least on
the 847 side.
The TRS jack is used for the HF (SSB) modes.? As shown in your
diagram, the PTT line from the TNC goes through the 2k resistor
to the TRS Tip, along with the transmit audio which is passed
through the 10uf DC blocking capacitor.? Receive audio from the
radio (TRS ring) is a direct connection to the TNC.? Ground /
Shield is common to both.
The trick is what is shown in the diagram to parallel the TRS
and mini-DIN connectors, giving access to the VHF FM modes as
well.? The 847 splits these out, and uses a different interface
scheme for the DIN connector, keeping PTT separate from the
audio circuit.?
Do note that you cannot use the CAT interface for keying the
radio.? The 847, for some bizarre reason, assumes the microphone
jack as the source when CAT is keying the rig, instead of either
of the rear jacks (TRS or DIN).? If you use CAT, you will find
you are able to key the rig, but have no audio transmitted.? I
had to use a separate USB-Serial dongle on my Raspberry Pi for
PTT, attaching one of its modem control lines (DTR / RTS)
through a buffer circuit.? I expect the RigExpert has this
built-in, so when configuring your software you need to make use
of the RigExpert's PTT feature and not the direct CAT interface.
Hope this helps,
Greg? KO6TH
|
One other question... what do the circles attached with dotted lines represent in the diagram??
|
|
|
Yes, You can. "+" sign means electrolytic
Alex LY4SA
|
Brian Howie GM4DIJ
Alan G3WXI aka G8AGQ
gw3fsp
Bill