I haven't seen many driver board failures personally (I typically only repair 7K's for local hams over the past 15 years, so I don't see a lot of units).? I have looked into the driver's design and signal levels at various drive levels and on all bands, while using an auto-tuner into various mismatches.? I do feel that antenna tuners and perhaps operation at LOW power seem to be a somewhat common thread for units that have multiple driver failures, but haven't seen direct evidence of it on units I've worked on.?
Many operators use antenna tuners to try to match antennnas well beyond the tuner's design spec.? This often damages the tuner, which then damages the radio.? Poor connections in the feed line and antenna are often intrmittent problems that lead to voltage/current transients that can damage the radio.? I feel that poor installations damage more radios than design flaws in the radio itself.
The added resistor change issued by icom was only for certain countries that had a different frequency range or band -- I forget the details.? Several postings indicated it was not effective.
Thermal measurements of the driver case don't indicate that the lack of thermal compound is a problem, but I always apply it when reinstalling the device.?
In short, I haven't encountered enough driver failures on rigs that I knew how they were being used at the time, to have an opinion about what the root cause of the failure is and what the proper fixes are.??
I doubt that a resettable circuit breaker will trip fast enough to protect the circuit, but haven't looked at their spec's for years, so maybe some exist.
The HF and VHF PA's will have factory-applied thermal compound.
My two 7K's are about 12 & 16 years old and had fairly heavy use (until the past few years), mainly mobile and portable, HF-UHF.? I've only fixed my radios 3 times and all of the failures were due to problems external to the radio.? I've also replaced the HM-151 mic switches with similar better-sealed switched when the original ones failed and replaced the poorly designed ATC style fuse holders used on some power cables with automotive style holders that bite through oxidation on the fuse blades.??
Hi Steve Yes i did all of the uhf and vhf Settings as i was in the menu, i did that this morning ,i found an old network cable and wired a switch and connected it to my Marconi 2955 and used the audio gen in that, i tested the output voltage of the marconi with my fluke and it was spot on, and for the rf power i used my digital 4391 bird meter, what do you think about the driver board mods, Thanks Dave 2E0DMB
On Tue, May 10, 2022, 10:18 AM davebb123456 <davidbrowne76@...> wrote:
Hi Joe the only thing is with a auto tuner, when tuning you are putting the radio into high vswr when it is tuning,? i will be using my radio with a? screw driver antenna , My driver board is still good, i do not know what revision it is , until i lift the PA board, i will do this today or tomorrow , as i can see that there is no heat sink compound on the driver board, and i will re-grease the other PA if dry like the uhf output was, Thanks Dave
Re: modding the Driver board , so it does not fry,
Hi Joe the only thing is with a auto tuner, when tuning you are putting the radio into high vswr when it is tuning,? i will be using my radio with a? screw driver antenna , My driver board is still good, i do not know what revision it is , until i lift the PA board, i will do this today or tomorrow , as i can see that there is no heat sink compound on the driver board, and i will re-grease the other PA if dry like the uhf output was, Thanks Dave
Re: modding the Driver board , so it does not fry,
The driver board is a definite weak spot. I've blown a couple up over the years.? The best solution I have found is to always use a good auto tuner like the LDG IT-100, even when using a resonate antenna. Not a perfect solution, but some added insurance.?
modding the Driver board? ? i see that icom did mod the driver board with an added resister to stop it self oscillating, and burning it self out,? does this work ? I have seen on youtube TRX Bench that he is still getting some 7000 with badly blown driver boards that already have this mod, i am thinking of doing the modes by SV8YM, and i am going to fit a self re-settable 1.5amp fuse, for the driver board power supply, Doing these mods is no problem for my skills , Thanks Dave 2e0dmb
Re: in the adjustment menu i can not get the driver idle current down to the 1 amp setting
Hi i just wanted to link the out come to the original post, Hi My mosfet RD60HUF arrived today from china i paid ?18 for it i should have found out the price from icom for this mosfet, ,i put it on my peak atlas dca 75 pro and it tested ok, The print on it was a bit light, and the legs were shorter then the data sheet and the drain leg did not have the slant,as on the data sheet, it may be second hand I Just zoomed in to the photo that i took before fitting and i think it is used as you can see the indents from were the screws have been,, there was no trace of it being soldered before , the legs are longer then the one that came out, i took photos just in case it did not work, But it did and it adjusted up to what it should 2.5a above the 00 reading that was 1.533amps, so i am very happy, the radio is not getting as hot,? i put the old mosfet that i removed on my peak DCA75pro and yes it shows as 2 diodes, Thanks for all of your help and info, Thanks Dave 2E0DMB ?
Hi My mosfet RD60HUF arrived today from china i paid ?18 for it i should have found out the price from icom for this mosfet, ,i put it on my peak atlas dca 75 pro and it tested ok, The print on it was a bit light, and the legs were shorter then the data sheet and the drain leg did not have the slant,as on the data sheet, it may be second hand I Just zoomed in to the photo that i took before fitting and i think it is used as you can see the indents from were the screws have been,, there was no trace of it being soldered before , the legs are longer then the one that came out, i took photos just in case it did not work, But it did and it adjusted up to what it should 2.5a above the 00 reading that was 1.533amps, so i am very happy, the radio is not getting as hot,? i put the old mosfet that i removed on my peak DCA75pro and yes it shows as 2 diodes, Thanks for all of your help and info, Thanks Dave 2E0DMB
On Mon, 2 May 2022, 18:39 James G5JIM via , <james.lang=[email protected]> wrote:
They can be ordered direct by email by the look of it?
On 2 May 2022, at 16:17, Mark J Culross <mjculross@...> wrote:
?Unfortunately, it doesn't look like he's doing direct sales anymore (text from the website link that was provided):
Details
?Published: 22 August 2021
Dear friends,
Official Ebay store is suspended until further notice as I have no time to handle it. The items will be available soon from partners or can be ordered directly per email. In any case 60 days free items return is accepted.?
On 2 May 2022, at 16:17, Mark J Culross <mjculross@...> wrote:
?Unfortunately, it doesn't look like he's doing direct sales anymore (text from the website link that was provided):
Details
?
Dear friends,
Official Ebay store is suspended until further notice as I have no time to handle it. The items will be available soon from partners or can be ordered directly per email. In any case 60 days free items return is accepted.?
On Sun, May 1, 2022 at 11:04 PM, James Dahl
<wi6x.73@...> wrote:
I bought DL5AL’s OPC-1443 alternative separation kit in May 2021 for 50 Euros. Attached is the manual.
On Mon, May 2, 2022, 10:20 AM Dallas N4DDM via <mylastname=[email protected]> wrote:
I can't answer your SDRPlay questions...?
Just be aware there are 3 current versions of the MFJ-1708...? ?The base 1708 is a true T/R Switch for old boat anchor rigs...? I don't think you want that version...?
The two newer ones let the transceiver and the SDR share the same antenna during receive...? So there is a 3 dB loss as two 50-ohm radios are connected to the antenna at the same time...? Think of it as a Tee Connector during receive...? During Transmit the transceiver is connected to the antenna and the input to the SDR is shorted to ground to protect the SDR's front end...
There is a different email address on his QRZ page.? Has anyone confirmed with him that he is not selling directly (outside of fleabay) at this point?
Russ KW6T
On Monday, May 2, 2022, 09:16:07 AM PDT, James Dahl <wi6x.73@...> wrote:
Unfortunately, it doesn't look like he's doing direct sales anymore?
I would email him support@...?and ask him... "items will be available soon from partners or can be ordered directly per email.” emphasis added.?
Jim WI6X
On May 2, 2022, at 8:17 AM, Mark J Culross <mjculross@...> wrote:
Unfortunately, it doesn't look like he's doing direct sales anymore (text from the website link that was provided):
Details
? Published: 22 August 2021
Dear friends,
Official Ebay store is suspended until further notice as I have no time to handle it. The items will be available soon from partners or can be ordered directly per email. In any case 60 days free items return is accepted.?
Unfortunately, it doesn't look like he's doing direct sales anymore?
I would email him support@...?and ask him... "items will be available soon from partners or can be ordered directly per email.” emphasis added.?
Jim WI6X
On May 2, 2022, at 8:17 AM, Mark J Culross <mjculross@...> wrote:
Unfortunately, it doesn't look like he's doing direct sales anymore (text from the website link that was provided):
Details
?
Dear friends,
Official Ebay store is suspended until further notice as I have no time to handle it. The items will be available soon from partners or can be ordered directly per email. In any case 60 days free items return is accepted.?
Steve W3AHL
WI6X Jim