开云体育

Low power output (<1W) on 40,80 & 160M only.

W7SS All Messages By This Member #53984 Has anyone run into this before? My 857D has very low power output on 40,80 & 160M only. The radio draws very little current on the bands with the problem 100W on other bands. Rx okay on all bands Did a full reset Did the relay clean procedure I can't find any path in the relay switching that only includes those bands.
Adrian Fewster #53985 开云体育 Is this on all modes, ie, ssb and cw/fm ? 73 vk4tux On 15/4/24 04:47, W7SS via groups.io wrote: toggle quoted message Show quoted text Has anyone run into this before? My 857D has very low power output on 40,80 & 160M only. The radio draws very little current on the bands with the problem 100W on other bands. Rx okay on all bands Did a full reset Did the relay clean procedure I can't find any path in the relay switching that only includes those bands.
W7SS All Messages By This Member #53986 Yes, the problem happens in all modes.
Juan Jiménez All Messages By This Member #53987 Are you on SSB? toggle quoted message Show quoted text On Sun, Apr 14, 2024, 2:47?PM W7SS via <kf7dur=[email protected]> wrote: Has anyone run into this before? My 857D has very low power output on 40,80 & 160M only. The radio draws very little current on the bands with the problem 100W on other bands. Rx okay on all bands Did a full reset Did the relay clean procedure I can't find any path in the relay switching that only includes those bands.
W7SS All Messages By This Member #53990 The ALC is full bars on the non working bands
W7SS All Messages By This Member #53991 No output when I key the mic in service menu # 28 When I exited the service mode the radio put out full power on 160M the first time I keyed it. Couldn't get it to do it again....
J.D. Barron All Messages By This Member #53992 Before panic, Have you tried it into a known good dummy load? The ALC for SWR is developed in the output of the radio and a high SWR would do just what you are saying. It is possible since the lower bands are what is giving trouble.
W7SS All Messages By This Member #53993 Edited Yes, it is connected to my service monitor with a good working wattmeter.? I'm reading about 100mW (+19dbm) on the bad bands and 100W + on the working bands. BTW: on the good bands the ALC is very low and when I momentarily key the radio with the coax disconnected the ALC reading doesn't change.
W7SS All Messages By This Member #53995 My bad, the reading in service menu # 28 is 166. Before I pulled the radio out of service I verified there was no power output on 2 different watt meters.
Adrian Fewster #53996 开云体育 Check with swr meter fitted inline on output ? 73 vk4tux On 15/4/24 07:10, W7SS via groups.io wrote: toggle quoted message Show quoted text My bad, the reading in service menu # 28 is 166. Before I pulled the radio out of service I verified there was no power output on 2 different watt meters.
J.D. Barron All Messages By This Member #53997 You might learn something with your scope on the input to the driver. I don't remember the bandpass arrangement on these, but when I get a chance I will take?a look. Perhaps some PIN diode bad. The receiver good on all bands? toggle quoted message Show quoted text On Sun, Apr 14, 2024, 4:01?PM W7SS via <kf7dur=[email protected]> wrote: Yes, it is connected to my service monitor with a good working wattmeter.? I'm reading about 20mW (+19dbm) on the bad bands and 100W + on the working bands. BTW: on the good bands the ALC is very low and when I momentarily key the radio with the coax disconnected the ALC reading doesn't change.
W7SS All Messages By This Member #53998 Yes, it's not an antenna SWR problem. I'm pretty sure the problem is with the relays in the bandpass filter section of the PA. The radio hasn't been used much in the last few years and I assume the relays didn't like not being exercised. I can certainly troubleshoot the problem but was trying to save some time by asking if someone else had the same issue and knew what the fix was.
W7SS All Messages By This Member #53999 As I stated in my original post the rx is okay on all bands.
Adrian Fewster #54000 开云体育 Yes relays/contacts etc are the most likely cause internal as you say. Sniffing the RF Volt level with a scope on TX path should identify the location. Good luck On 15/4/24 07:43, W7SS via groups.io wrote: toggle quoted message Show quoted text Yes, it's not an antenna SWR problem. I'm pretty sure the problem is with the relays in the bandpass filter section of the PA. The radio hasn't been used much in the last few years and I assume the relays didn't like not being exercised. I can certainly troubleshoot the problem but was trying to save some time by asking if someone else had the same issue and knew what the fix was.
W7SS All Messages By This Member #54001 Thanks Adrian, I'll chase down the relay problem tomorrow and post my results.
VA2XMP - Stephane Laroche All Messages By This Member #54002 Same issue on my 857D in locator FN35BQ. VA2XMP toggle quoted message Show quoted text Le dim. 14 avr. 2024, à 16 h 42, W7SS via <kf7dur=[email protected]> a écrit?: The ALC is full bars on the non working bands -- STEPHANE? ?(VA2XMP) CanWarn, CFARS, VA2GCU,?Winlink RMS: VA2XMP 24/7 VOIP: 5143169085 Hamshack Hotline: 5500000885? HamOverIP.ca:? 721011
W7SS All Messages By This Member #54003 Did you fix it?
Mike All Messages By This Member #54004 开云体育 Hi I had same problem ?last year (although different bands), reset didn’t do anything. ?it was a relay I believe. Yeasu fixed it under warrantee. Cheers Mike Mike Christie Cell?+61 407 998208 toggle quoted message Show quoted text On 15 Apr 2024, at 02:47, W7SS via groups.io <kf7dur@...> wrote: ?Has anyone run into this before? My 857D has very low power output on 40,80 & 160M only. The radio draws very little current on the bands with the problem 100W on other bands. Rx okay on all bands Did a full reset Did the relay clean procedure I can't find any path in the relay switching that only includes those bands.

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