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Re: IC7000 no HF Transmit
Bob, Thanks for the encouragement I have considered all of the suggestions for troubleshooting the problem I have with the IC7000.? I have tried to trace the HF RF path with an oscilloscope from where the signal comes through the cable from the main board to the PA board.? I have traced the signal and inspect all components through to the output at ant1.? The signal seems to loose its punch where the PA FETs combine into the L305 transformer.? The bias setting of the PA FETs seem to be correct.? After the signal reaches the rx/rx relay it passes through the selected HPF where it reaches ant1.? The resulting signal is only a few milliwatts.? I have tried to keep the setting in SSB and I see modulation when speaking into the microphone. ? I know it is difficult to troubleshoot the issue remotely but I appreciate any and all ideas. Thanks Tommy. KF4RWG On Sat, Jan 25, 2025 at 6:31?PM Bob via <W4JFABob=[email protected]> wrote:
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Re: IC7000 no HF Transmit
Well this is #30 then. That's OK because when the rest of us have this problem we'll appreciate?every?one of?these replies. Keep on writin' you guys. Bob W4JFA On Thu, Jan 23, 2025 at 4:40?PM Geoff via <vk3zgw=[email protected]> wrote:
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Re: Japan version needing frequency expansion on 2m/440
Andrew K5KNM
Thanks for some more responses, I should have looked into it more carefully before buying the Japan version. These radio's can sometimes be scarce to buy used when looking for one and at the time, all I can find was the Japan version. My guess was that all versions were essentially built the same with the same components and the MARS mod I found online would expand "all" the frequencies. I see now this is not the case.? It's still a good radio and covers enough 2m for me and has plenty of HF range that will suit me.
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Thanks again, Andrew K5KNM |
Re: Japan version needing frequency expansion on 2m/440
开云体育Andrew, ? I wish there was a universal way to communicate this to all: ? Domestic Japanese amateur radio units are blocked at the CPU level to only be able to transmit on Japanese amateur radio bands.? There is no way of opening the bands short of replacing the CPU. This is because of Japanese law. This is true for VHF and UHF.?? I understand that some have figured out how to open frequencies on HF, but this is unconfirmed. ? Export units have their own frequency bands depending on the country , but they can be modified for extended transmit.? That is, the EU radios have frequency restrictions somewhat similar to the domestic Japanese units, but the EU radios can be modified to operate frequencies that are available to us in Region 2 (i.e. extending 144-146 MHz to 144-148 MHz. ? My assumption on the Japanese newer units is that if new amateur radio frequencies are available in Japan, that ICOM could potentially add them by a firmware update, but this is only a guess. ? ‘73 de Jim N2ZZ ? From: [email protected] <[email protected]> On Behalf Of Andrew K5KNM via groups.io
Sent: Saturday, January 25, 2025 10:29 AM To: [email protected] Subject: [ic7000] Japan version needing frequency expansion on 2m/440 ? Hello all! I recently purchased the Japan version of the IC-7000 for use in my my shack while my other USA version one will stay as a mobile. Of course there are some difference in frequencies between this one and the USA version. Mainly the 2m/440 bands is where the most differences are . On this model, 2m is only 144 to 146 mhz and 70cm is 430 to 440 mhz. . It appears the typical MARS mod does not expand these 2 bands to get the full US frequencies. I would like to expand these 2 bands so I'm asking here if anyone knows if this possible and what would be the procedure be. Thanks! ? 73 Andrew K5KNM |
Re: Japan version needing frequency expansion on 2m/440
Unfortunately almost all Japanese radios are set to conform to Japanese laws and are not modifiable to meet US US specifications.?
The Japanese "FCC" does not allow the radios modification and these can not be changed without major changing boards or major components.
This is why Icom will not work on a Japanese version of a radio nor warranty one here as parts may not be available and they were produced for that region.
Best to not buy an out of region radio for use in the US.
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Japan version needing frequency expansion on 2m/440
Andrew K5KNM
Hello all!
I recently purchased the Japan version of the IC-7000 for use in my my shack while my other USA version one will stay as a mobile. Of course there are some difference in frequencies between this one and the USA version. Mainly the 2m/440 bands is where the most differences are . On this model, 2m is only 144 to 146 mhz and 70cm is 430 to 440 mhz. . It appears the typical MARS mod does not expand these 2 bands to get the full US frequencies. I would like to expand these 2 bands so I'm asking here if anyone knows if this possible and what would be the procedure be. Thanks!
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73 Andrew K5KNM |
Re: IC7000 no HF Transmit
Forgive me if this has been mentioned before but as this is the 29th reply I haven't gone back and read everything.
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I always go first to where the effect of a fault is obvious without any ambiguity, in this case the rf output ie Ant 1 connector, working back to eliminate ALL the stages involved, including in this case the SO32 jack.
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Good luck.
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Geoff
VK3ZGW |
Re: IC7000 no HF Transmit
Thanks
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?Get BlueMail for Android ? On 23 Jan 2025, 16:18, at 16:18, "Tommy Wooten via groups.io" <kf4rwg@...> wrote:
James, |
Re: IC7000 no HF Transmit
James, The link to all the updates of the Ic7000 service manual?is here: They are all included, newest to oldest. Tommy On Wed, Jan 22, 2025 at 8:34?PM James Tiberius via <nono2212000=[email protected]> wrote:
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Re: IC7000 no HF Transmit
Apply a DC via a resistor to JHFOR, see if the power folds back and current drops
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Then you can work on it and trace 73 Andrew ?Get BlueMail for Android ? On 23 Jan 2025, 15:51, at 15:51, Andrew Lenton <a@...> wrote:
Hi Tommy again, |
Re: IC7000 no HF Transmit
All well and good, but there must be an O/C some where in the TX path! Or a S/C cap
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73 Andrew ?Get BlueMail for Android ? On 23 Jan 2025, 15:43, at 15:43, "J.D. Barron via groups.io" <jeter.d.barron@...> wrote:
The power control will not reduce power if the forward power |
Re: IC7000 no HF Transmit
Hi Tommy again,
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Also looking at the block diagram, I can see the TX and RX share the LPF, which actually turns out to be Band Pass filters!! Fairly wide. How does the RF get to the filter board is it a track mini co-ax, as you need to break in and see if you can measure the power before the filter, or I/p to relay? I know this is all on one board, do isolating is tricky, to remove this board, you have to desolder the pre amp board, if you do not have a proper de soldering station, then stop. You need to find out where the RF is going or being blocked. 73 Andrew If you were closer I would repair free of charge! ?Get BlueMail for Android ? On 23 Jan 2025, 15:32, at 15:32, Andrew Lenton <a@...> wrote:
Hi Tommy, |
Re: IC7000 no HF Transmit
The power control will not reduce power if the forward power measurement circuit is not receiving power. As it is after the bandpass filters and that is where the problem seems to be. Currently the power is only controlled by the current limit settings to the CPU.
I suggest signal tracing in SSB and adding only a small audio signal to limit the power loading to reduce the load on the PA transistors.
This is why I brought this up earlier.
All of the above is from perhaps incorrect recollection, however. I do believe that this is the case. Power cannot be turned down if the forward power measuring circuit does not sent the power level back to the CPU.
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JD
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KE4MD |
Re: IC7000 no HF Transmit
Hi Tommy,
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Can you turn the power down on FM or CW to a few watts? This will help with signal tracing ?Get BlueMail for Android ? On 23 Jan 2025, 15:13, at 15:13, "Tommy Wooten via groups.io" <kf4rwg@...> wrote:
Andrew |
Re: IC7000 no HF Transmit
Andrew Yes the current supply varies with usb modulation.? That is why I put the mode to FM for the supply current test.? The odd thing to me is that the supply current is substantially higher with the higher bands.? I do see a smaller but discernible ssb modulation in current at 160M. The FM transmit at 10M a quick rise in heat on the PCB near L303.? I do see a high level of RF at the output of each of the PA transistors and the level is substantially lower at the L305 output and down stream through the LPF to the ANT1.? As a result the output power at ANT1 is only milliwatts on the external power meter and dummy load. I hope this description help's. ? Thank you Tommy On Thu, Jan 23, 2025 at 9:18?AM Andrew Lenton via <a=[email protected]> wrote: Hi, |
Re: IC7000 no HF Transmit
Hi,
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You need to find out if there is RF power being generated.? The current is a clue, so switch to USB key up you should draw a few amps bias current, the speak CQCQ ect, the current should peak in sympathy with you voice. If it remains high you have a fault in the PS. If the current remains the same check mic gain if ok, then you have no drive. KR Andrew Get back to me Do you have a spectrum analyser? ?Get BlueMail for Android ? On 23 Jan 2025, 01:33, at 01:33, "James Tiberius via groups.io" <nono2212000@...> wrote:
Thanks Tommy |