MFJ-998 tuner Excessive RF Radiation
Has anyone experienced excessive RF radiation from their MFJ-998. When I run a signal (any mode) on 80m more than 70 W? through the tuner I have adverse effects from several devices including my oven, computer monitor and remote controlled lights, all devices have RF chokes on them. When I bypass the tuner I do not have the same issues.
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When I use the 1708B-SDR it will occasionally put the radio in transmit.? This doesn't happen if the unit is not in the loop.? At first I thought it was RFI so I have toroids on everything and a common mode choke on the coax from the antenna.? Only happens when I am using the 1708.? It happens if I just use RF sensing mode or in combination with CTRL to PTT.? Any ideas?
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MFJ 1263 Yaesu - Yaesu pin set
I'll try this again with some photos this time.? Help needed as I'm still drawing a blank on this.? Hello,? I don't know if I'm being stupid or I just cant see it in the manual.? I have a Yaesu FT-847 and an FTDX101D I use a mix of Microphones, But want to tidy the desk and only use two so I bought the MFJ-1263 Microphone/Radio switch.? Microphones are Yaesu M100, Heil Pro 7 and Heil HM12. I will keep the Pro 7 in line all the time and mix between the other two.? I can't seem to find any information on the pin settings for Yaesu to Yaesu in the manual.? Like I stated, I'm probably being stupid and I am missing it completely. The factory pin settings don't work.? Please put me out of my misery. If you have a similar setup, please share your pin set photos.?  
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Ken . . .
(see below)
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On Tue, Jan 24, 2023 at 03:23 PM, Ken K wrote:
From my reading by default it's prevented so high voltage and damage won't happen.
It's suppose to allow slightly more or less capacitance and inductance
than what's available by default.
I run low power and wanted to find out if either more or less cap/Ind would
help with some tuning.
I have read the manual a few times and I am still a bit confused
how you extend the range.
I approved your post for today's date, a follow-up of this post, but it hasn't yet appeared on the GIO site nor in my inbox, so I'll just respond here.? ? ?? I'm replying from the group site, but often, when I do so, the formatting goes kaput and all the text gets run together with no paragraph breaks. Hopefully this will remain formatted. If it doesn't, my apologies. I'll leave a few extra spaces between paragraphs just in case.? ? ?? The group is what the members make of it. There are 133 members, some of whom have this tuner (I have one myself). No one person, or even several persons, can make a group work out well for the rest of the members. More time will tell if this group was not going to be a group worthy of being here. If the group doesn't work out, it can be "recycled" to a different ham radio group for a different purpose, something that will be useful to it's members. We're not there yet, though. It takes a few years to see how things work out. The Icom group I started at first didn't seem to be picking up steam, but it gathered momentum and I believe it's now a useful resource to Icom radio and equipment owners. This group is a little newer so let's give it another year or so. (Yes, it does take some time to get a group to be well-established.) I am glad I took some time to attempt to answer your question because I learned a few things about my 993B tuner that I didn't know were there before. I bought mine refurbished at Hamvention in Xenia, OH, a few years ago. (I saved about $100 buying it refurbished.) I will be changing the power limit to 150W now to get a larger range of SWRs that it can match. Of those (probably several) members here who have this tuner, I would guess that none of them have ever tried to override the default chosen C and L values. In your case, I can see where you might benefit from doing so, but this tuner requires 10-20 watts for "maximum SWR tuning accuracy" (Page 1 of the manual), so it's not really intended to be a QRP tuner. The minimum power required to get any tuning is 2 Watts (page 1).? ? ? ?? ? I can see where you might be confused in the wording of the manual about increasing the C and L limits, but I think I might be able to clear up some of the matter. On page 20, it says that you can change the maximum C and/or L value(s) as long as that doesn't go outside the limit for the power and frequency. So let's say that the tuner finds an SWR match of 1.4:1 and it stops there. You can fiddle with the L and C values to get a lower SWR (or a higher one, if you really cared to do so), as long as the final value(s) are within the limits that protect against arcing from too high of a voltage in the matching circuit. So you bump up the C value but try to go over the limit, and it won't let you. Of course, that's by design.?? ? ?? Now, on page 20, which also explains some of the above on the limits of C and L values, explains that the upper values of L and C are factory-limited according to power and frequency. So if you are using more than 150 W (up to the maximum of 300 W), it will restrict you more than if you are using 150W or less. For under 300W, it will match 6 to 3200 Ohms impedance, while over 300W, it will match 6 to 1600 Ohms. That translates to an SWR maximum of 64:1 and 32:1 respectively. The factory default power setting is for 300W. If you haven't changed it from that, you're limiting yourself to a much narrower range of potential SWR matches than if you change that setting. The way to do that is under Power Level Menu on page 17. You can also change the target SWR (page 17) and the auto tune SWR threshold (page 18).? As I read it in the manual, the best you can do is to set your 993B power level to the 150W limit, and perhaps make it more sensitive to when it will try to tune for a lower SWR in the auto tuner threshold and set the target SWR to just under the SWR limit set by the radio manufacturer, so that you're not trying to tune down to a 1:1 SWR when it's not necessary. Unless the radio is folding back power to compensate for a high SWR, you're not gaining much (if anything) by going for a perfect match. (If you want to discuss this sort of thing further, may I suggest starting a new thread in the ham-antennas group:???and discussing it there. Now, if you are dealing with a transmitter that doesn't have fold-back SWR protection, then you may have something to gain by aiming for close to perfection. Otherwise, in the time it takes to fiddle and diddle to manually tweak the SWR to make it better, you may have missed making that rare contact you were hoping to have a QSO with.? One section I don't completely understand is about the Intellitune Menu on page 19. It says you can turn off the Intellitune algorithm. It doesn't specify if that means you can go full manual with the L and C values or not. I would interpret it to mean that you can use it as a full manual push-button tuner. You should be able to verify that quite easily by turning off the algorithm and seeing if it does, indeed, allow you to change the L and C values manually once you've done that. If you do this, please let us know. Someone else might be interested in this information. (BTW--I still haven't seen the follow-up message by the original poster on the group site or in my inbox.) Donald KX8K
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Re: Autotuner for Drake R8B?
Don, thank you so much for your input.? I kept looking at the different auto tuners on the internet and wondered about the required signal. I wasn't sure how I was going to accomplish that...... LOL Thanks again.
Best
Bill
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Re: Autotuner for Drake R8B?
Bill . . . On Thu, 11 Jan 2024 14:02:03 -0800, "William Rowe" <wmrowe@...> wrote: Instead of getting up and walking to my radios, I would love to have an autotuner to do the work for me. Any suggestions? All of the auto tuners I know of require a small signal to be transmitted so that the SWR sensing circuit can work with the tuner logic to find a low SWR match. That would require a license to transmit on the frequencies of interest. Even with a ham license, you would not be allowed to transmit on SW broadcast frequencies. However, you could use an active preselector like the MFJ-1045C. A passive preselector will introduce insertion loss. Even an active one introduces the same loss, but it will have a preamplifier built in to compensate for that and possibly to boost signals a bit compared to now using one. Whether this would be worth trying is a question I can't answer. I think you're fine with what you have now. An auto tuner requires a signal, which you can't provide since you're not licensed on the frequencies of interest. If you have plenty of gain and don't have trouble pulling in your stations, then I doubt a preselector would help. A manual tuner, like an auto tuner, would introduce insertion loss, as would a preselector (though an active preselector would have a preamp built in to compensate for this loss). Donald KX8K ---------------------------------------------------- Some ham radio groups you may be interested in: /g/ICOM /g/Ham-Antennas/g/HamRadioHelp /g/Baofeng/g/CHIRP
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I would appreciate recommendations on antenna autotuner for receivers Drake R8B and Drake SW8. I am not a ham, but have listened to SW and ham operators for the past 65 years. I'm 73 years of age and thinking maybe it's time to get licensed (not sure my brain could do it.... lol). My radio shack (tool shed) is arranged so that my radios and existing MFJ-959C tuner and antenna switch are kiddy corner to my Dell AIO computer and TV (to avoid interference). I control the R8B with Fineware software from my computer.? I have two antennas, a Delta DX-SWL sloper (60'), and the MFJ-1886 loop antenna with rotor. Instead of getting up and walking to my radios, I would love to have an autotuner to do the work for me. Any suggestions?
Thanks in advance.
Bill?
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Re: S-match tuner and MFJ modification
I have seen a similar design in one of the ARRL handbooks from many years ago.....
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Jimmy . . . On Tue, 25 Jul 2023 11:17:34 -0700, "Jimmy Moser W4MUF" <wxgeek@...> wrote: My MFJ-148RC has stopped receiving the tiime signal from WWV and thus the time is not kept updated.? Anybody else have a similar problem ? I don't know if you'll get an answer on this one, but it looks a lot like the ones LaCrosse Technology make and it might be a re-branded clock made by them. That doesn't help a lot, I know, but some suggestions online for this sort of clock say to replace the batteries and try letting it update. Leave it without batteries for 10 minutes to clear anything from the circuits. It's possible either the battery is just low enough that the update feature won't work or that the electronics inside got confused and a bit if flipped the wrong way and resetting it this way might fix it. If you moved the clock from where it was working, you might have it in a dead zone for WWV reception. Perhaps you added a new electronic device to your house and now have broadband RFI (radio frequency interference) covering up the WWV signal, which is likely weak anyway. A good test of the RFI theory would be to take it with you somewhere away from electronic devices, like camping in an area where lots of campers DON'T camp (they bring their electronic doo-dads with them, which brings the radio noise, too, from those little power blocks like phone chargers). See if it updates overnight or whenever it's said to update. You could also turn off all power to the house a little before update time, wait for the update, and see if it happens. Turning off the mains circuit breaker will at least stop all noise coming from electronics in your home. If it does update, when camping or with the power off, you then can search for the culprit, or decide to put up with it rather than to inconvenience yourself without your favorite electronic noise-maker. If you do find it's something in your home, we can go from there. If not, then your clock might just have a broken feature. Donald KX8K ---------------------------------------------------- Some ham radio groups you may be interested in: /g/ICOM /g/Ham-Antennas/g/HamRadioHelp /g/Baofeng/g/CHIRP
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My MFJ-148RC has stopped receiving the tiime signal from WWV and thus the time is not kept updated.? Anybody else have a similar problem ?
Jimmy
W4MUF
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S-match tuner and MFJ modification
While researching balanced tuners, I ran across a website that describes the "S-match" tuner.
Digging a little deeper revealed a detailed modification of a?MFJ-989 to an S-match.
Has anyone here done that and if so, what were the results? More generally has anyone used an S-match and how well does it work?
WB6YZZ
Prineville, Oregon
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Howdy;
?Looking for help or suggestions here. I have an MFJ 1278 original, not the b version. It will not respond to signals coming in, but will transmit tones and the Digi I am connecting to responds.
?I am looking for a better schematic. I have the book, but the drawing is small and hard to see. Don't know if doing a scan will work.manual is for rev 2, my board is ver 7)
?Anyhow, this is driving me nutz, and looking for help or suggestions.
?Thanks
?73
?Mike - N7ZEF
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Steven . . . On Fri, 19 May 2023 15:32:23 -0700, "Steven Greenfield AE7HD via groups.io" <alienrelics@...> wrote: This is the thread, and there is only one picture posted in it. Not all of us use the web interface to read groups.io posts. I, too, didn't know what the member was referring to and just marked the post as read in my email client. Those using email clients to read the posts won't easily be able to figure out which post it was and how long ago it was that the post was made. Also, many people reading the posts in an email client don't have threading turned on, in order to see posts in chronological order, and some delete messages once they are read, so posts that include no quoted reference make us wonder what the person is talking about. I've given up on answering posts from this person since he doesn't include any referenced quotation of the previous post being referenced unless it's clear what it's about and no quote is needed to make it clear. It's considered good netiquette to always include some of the previous message so the reader can connect the dots easily. Donald KX8K ---------------------------------------------------- Some ham radio groups you may be interested in: /g/ICOM /g/Ham-Antennas/g/HamRadioHelp /g/Baofeng/g/CHIRP
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On Mon, Apr 24, 2023 at 10:01 AM, Lou Everett, Sr. wrote:
What are you talking about?? You did not include the thread so we don't have a clue what you are referring to.
This is the thread, and there is only one picture posted in it. ? -- Steven Greenfield AE7HD
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On Mon, Apr 24, 2023 at 10:01 AM, Lou Everett, Sr. wrote:
What are you talking about?? You did not include the thread so we don't have a clue what you are referring to.
?
Lou WA5LOU
Enhance your calm, fellow citizen. This =is= the thread, and there is only one picture posted on it. By HB9DDS. Sheesh. ? -- Steven Greenfield AE7HD
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Re: MFJ-1786 Remote Control
Glad somebody else does that.....I cleaned out my closet and garage shelves this week and found antenna parts that I've been looking for for 6 months.....
73
B.J. Watkins K5BJW
On Monday, 15, 2023 at 08:16:37 PM CDT, Gary Harmon <k5jwkgary@...> wrote:
Cancel the lost dog notice.? Remote Control has been found.? If it was a snake, I would be bit. ? 73, ? Gary/K5JWK ?
From: [email protected] < [email protected]> On Behalf Of Gary Harmon via groups.io Sent: Monday, May 15, 2023 9:10 AM To: [email protected]Subject: [MFJ-Amateur-Radio] MFJ-1786 Remote Control ? I can't find my remote control and was wondering if anyone has one needing a new home in south Texas.? Cash or trade available.
Best 73,
Gary Harmon
k5jwkgary@...
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Re: MFJ-1786 Remote Control
Cancel the lost dog notice.? Remote Control has been found.? If it was a snake, I would be bit. ? 73, ? Gary/K5JWK ?
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From: [email protected] < [email protected]> On Behalf Of Gary Harmon via groups.io Sent: Monday, May 15, 2023 9:10 AM To: [email protected]Subject: [MFJ-Amateur-Radio] MFJ-1786 Remote Control ? I can't find my remote control and was wondering if anyone has one needing a new home in south Texas.? Cash or trade available.
Best 73,
Gary Harmon
k5jwkgary@...
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Re: MFJ-1786 Remote Control
Cancel my missing person request.? If it had been a snake I would be bitten. ? Thanks and 73, ? gary Gary H. Harmon Jr. RETIREMENT – Everyday is a Saturday except Sunday. ?
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From: [email protected] < [email protected]> On Behalf Of Gary Harmon via groups.io Sent: Monday, May 15, 2023 9:10 AM To: [email protected]Subject: [MFJ-Amateur-Radio] MFJ-1786 Remote Control ? I can't find my remote control and was wondering if anyone has one needing a new home in south Texas.? Cash or trade available.
Best 73,
Gary Harmon
k5jwkgary@...
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I can't find my remote control and was wondering if anyone has one needing a new home in south Texas.? Cash or trade available.
Best 73,
Gary Harmon
k5jwkgary@...
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Have you tried MFJ?
Lou WA5LOU
Hi fellow operators?
I am looking for a power switch and? button cap for my 998. I have pretty much exhausted thingybay and amazon, Aliexpress etc are a no go and I cant find a UK stockist that does that size of button cap.
The 6 pin switch I can source so can anyone point me to either a complete switch/button cap assy or just the button cap please.
Failing that has anyone stripped one for spares?
Regards
Garry.
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Mick
Leonard McDonnell EI2JHB
William Rowe
George LaBelle
B. J. Watkins
Lou WA5LOU