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Re: UHF FM Transmit Power
On Sat, 24 Mar 2018 08:05:37 -0700, you wrote:
No, you do NOT remove the PA board to replace the UHF transistor. You have to remove the PA only for the driver. Just remove two screws, unsolder the cover which is over the UHF transistor, plug in the new one, screw&resolder the cover shield and that's it. Takes 30 minutes. No adjustments necessary, although it is ok to do with older IC7000 units because electrical parameters shift over time. The adjustments are tricky and complicated, better leave as is. The main difficulty is to get exactly 3, 20 and 30 mVolt 1500 Hz at the microphone input. Everything else is straightforward. And you must provide exactly 13,8 Volt at the transceiver DC input during transmit! OE8UWW |
Re: UHF FM Transmit Power
Correction:? You do NOT have to remove the PA board, unsolder the Driver pins or remove the flex cables on the 7K to replace the UHF PA.?The last one I did had additional problems that required replacing other components to correct a bias issue.? The UHF PA is accessible by just removing the bottom cover.
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Steve, W3AHL On Sat, Mar 24, 2018 at 08:05 am, Steve W3AHL wrote: On Fri, Mar 23, 2018 at 01:04 pm, <k6msm@...> wrote: |
Re: UHF FM Transmit Power
On Fri, Mar 23, 2018 at 01:04 pm, <k6msm@...> wrote:
Thank you, both.? I will look into this.? Is it something I can replace with my unsteady hands or should I send to Icom?The ALC meter acts differently on constant carrier modes like FM and RTTY.? A high reading on 2M is OK, being 0 on 440 means that since TX output power is too low the ALC circuit is not trying to reduce the IF gain to maintain the desired power.?? Replacing the UHF PA is relatively simple.? But getting to it takes a little work.? The driver board is soldered to the PA board, so it has to be unsoldered.? Make sure each pin wiggles before trying to remove the PA board, otherwise you may pull a plated-through hole out, which will have to be repaired.? The PA board has ribbon cables that attach it to the Main board.? Carefully pull them out and make sure the plastic stiffener on the back side remains? attached.? On older cables it often comes loose, in which case the cable should be replaced.? It centers the cable in the connector and assures the contacts are properly aligned.?? After the unit is back together you will need to do the TX Adjustments in section 4-4 of the Service Manual.? Specifically you must do:
The UHF PA is sensitive to voltage spikes greater than about 35 volts peak, which are often found on a vehicle's 14 VDC battery supply, due to the starter motor counter EMF when starting the engine.? Since I started using a Littelfuse TVS (transient voltage suppressor) in my mobile RigRunner Power Pole distribution units, I have had no further UHF PA failures in over 10 years.? There is a document in the Files section that describes how to add a TVS diode to a RigRunner to clamp the power spikes to a safe level. Steve, W3AHL |
Re: UHF FM Transmit Power
On Fri, 23 Mar 2018 10:54:57 -0700, you wrote:
Hello, I just replaced one in my 7000 and I bought them here: It's an absolutely easy job, given you know how to solder. No adjustments needed. Yeah, and never say "SODDER", tha's nigger slang. OE8UWW |
Re: UHF FM Transmit Power
I can add that the UHF final is at least one of the easier ones to swap out in the 7000. Steve VE7FM On Fri, Mar 23, 2018, 12:39 Paul Hansen <pwhansen@...> wrote:
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Re: UHF FM Transmit Power
k6msm@soara.org
Thank you, both.? I will look into this.? Is it something I can replace with my unsteady hands or should I send to Icom?
Also, the ALC meter doesn't seem affected by changing mic gain on FM.? On 2m it's always too high (beyond the scale) and at 440 it's always 0.? Not sure if this is ok and/or related. FYI at 100% power it only puts out 8W on 440.? I probably should dial back the RF % until I get it fixed to avoid further damage. 73, Mike K6MSM |
Re: Hex command to play stored voice message #1 over the air?
Don't think you can but you can always press F1-F4 manually. N3FJP can play sound files.? Record and save your audio files, then navigate to each sound file from N3FJP.? Sorry I cannot be more specific because I don't have the N3FJP logger open in front of me.? But it has a voice keyer memory just like it has a CW Memory Keyer. Steve WA8Y? On Thu, Mar 22, 2018, 7:24 PM Robert Snell <rob@...> wrote:
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Re: UHF FM Transmit Power
开云体育The 7000 uses separate finals for HF, VHF and UHF but the same driver. I you get full power output on HF and? VHF, I bet the UHF PA is gone. It’s an RD60HUF-1 and they go bad for some reason. ? Thank you, ? Paul W. Hansen, W6XA ? ? From: ic7000@groups.io [mailto:ic7000@groups.io] On Behalf Of k6msm@...
Sent: March 23, 2018 17:55 To: ic7000@groups.io Subject: [ic7000] UHF FM Transmit Power ? Hello, |
Re: UHF FM Transmit Power
99% chance the UHF final needs to be replaced. Last time I needed one had them in stock. Steve VE7FM On Fri, Mar 23, 2018, 12:08 <k6msm@...> wrote: Hello, |
UHF FM Transmit Power
k6msm@soara.org
Hello,
I have a used IC-7000 and am concerned about the UHF FM transmit power.? I think it might have a problem now that I've tested it with a watt/SWR meter. I know that the UHF spec is lower (35W), but it takes 80% RF power to get only 5W.? At 50% RF power I get about half a watt out.? To compare, it only takes 15% to get 5W on VHF FM.? SWR is effectively 1:1 on both bands. Is this normal or is something probably fried on the UHF side? 73, Mike K6MSM |
Hex command to play stored voice message #1 over the air?
Hi all, Rob KQ3Q |
Re: 440 Band Off Frequency
The Reference Oscillator is subject to frequency drift due to several causes, which result in the need to recalibrate it using the OTHER menu #51 adjustment.? I would try that before sending it in for repair.? While the oscillator is specified to have +/- 0.5 ppm frequency stability, that is only the short term stability with reference to gradual termperature change.? The long term aging is specified at +/- 1 ppm/year.? The oscillator frequency is voltage controlled via a D/A converter on the CPU, which its datasheet does not fully specify long term drift characteristics but probably exceeds 1 ppm.? I have seen units needing adjustment that be in the range of about 2 KHz shift on 440 MHz, but seemed to remain within spec afterwards.
I tend to recalibrate my 7K's Ref Osc about once a year.? Allow the unit to warm up with power on in the typical ambient operating environment for at least 30 minutes.? Then zero beat to the highest WWV frequency you can receive or calibrate as others mentioned to another reference signal (but not in FM mode, since the frequency accuracy will not be adequate for other modes).? ?Recheck the calibration occasionally to verify it is reasonably accurate still.? If not, there may be a problem with X1 on the DDS board or some other part.? I've never personnally known any of the loca hams to have to repair a 7K due to frequency drift that couldn't be adjusted with the menu 51 calibration (there's a reason it's there!), but VCO's can certainly fail, as can the DDS IC's and their controlling register chips. Steve, W3AHL |
Re: 440 Band Off Frequency
Kenneth W. Campbell
Hi Dennis,
Thanks for taking the time to reply, I really appreciate it! I've been exchanging emails with Scott Malcolm of MTS Technical Services about the problem. He fixed a 718 for me last year with excellent results. The part in question is the TCXO. Scott says it's rare that they cause a problem but he's seen it before. Says if performing the master reset procedure doesn't clear the problem, that part is about the only thing that would cause the error. The higher the tuned frequency, the greater the error. As I traded a 706 MKII-G straight across for the 7000, it's worth having the repair done! All said the best, Ken N6PCD |
Re: 440 Band Off Frequency
On Sat, 17 Mar 2018 22:00:09 -0700, you wrote:
Hi all,The IC-7000 oscillator is very temperature dependent. You have to re-adjust the reference frequency in the OTHER menu when temperature changes a lot and causes frequency drift in the higher frequency ranges, especially VHF and UHF. Find a commercial station in the VHF or UHF, tune in SSB with an offset of 500 Hz and adjust the difference tone to 500 Hz using a smartphone app. Im am using the app "Spectroid", but there are many others. Alternatively you could use a guitar tuner at 440 Hz. If the frequency iy stored in memory, the whole procedure takes less than a minute. OE8UWW. |
Re: 440 Band Off Frequency
Ken, I had this problem on one of my IC7000. We noticed that it was ever so slightly off frequency on HF.? It was usable on VHF but not UHF, but I didn't use it there.? Turns out the primary oscillator (not the right name but I can't think of it right now) was off frequency.? The amount it was off on HF and even VHF was small.? However, to get to 440, the main frequency gets multiplied several times and so does the error and my radio was way off on 440 just like yours. I sent it in to Icom repair in Michigan.? Matt repaired it.? If it is off a little, it can be adjusted.? In my case he needed to replace something that wasn't cheap.? So if you don't use it on 440 you might not want to bother. I suggest you talk to Matt at SAR Technical Services,? 269-429-2334. Best Regards, Dennis, N8ERF On Sun, Mar 18, 2018, 1:14 AM Kenneth W. Campbell <n6pcd@...> wrote: Hi all, |
440 Band Off Frequency
Kenneth W. Campbell
Hi all,
I've a interesting problem with my 7000: Seems that the 440 MHz band, FM mode, has gone off frequency 5 kc low. In order for, say, 446.300 to have clear audio, the VFO needs to be at 446.305. ?The problem is consistent on the 440 band. This is not a problem on the 144 MHz band. I've already performed the master reset procedure. Any ideas? All the best, Ken N6PCD |
Re: You have been added to ic7000@groups.io
开云体育You can use any email address.? If you have not changed your
email, the new group.io will be on Google group.io but you email
msg will stay the same.? I rarely visit is group site, I went to the group.io and changed my email address to one I can read on my phone. I am still receiving IC-7000 group posts to my old email address,
and now to my new email address.? Soon I will unsubscribe to the
Yahoo group.? You should go the the new group website;? /g/ic7000 Hope this helps.? On 3/11/2018 6:34 AM, J Chaloupka via
Groups.Io wrote:
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