Hf+50 MHz power loss

ik0oky All Messages By This Member #786 Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
Andrew Lenton All Messages By This Member #787 How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: toggle quoted message Show quoted text Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
ik0oky All Messages By This Member #788 开云体育 Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: toggle quoted message Show quoted text How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
Andrew Lenton All Messages By This Member #789 开云体育 Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: toggle quoted message Show quoted text Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
ik0oky All Messages By This Member #790 开云体育 Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: toggle quoted message Show quoted text Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
Andrew Lenton All Messages By This Member #791 开云体育 You will get there Get On 24 Aug 2023, at 18:56, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: toggle quoted message Show quoted text Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
Andrew Lenton All Messages By This Member #792 开云体育 The HF PA is under the main board, tricky to get to but doable 73 Get On 24 Aug 2023, at 18:56, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: toggle quoted message Show quoted text Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
ik0oky All Messages By This Member #793 开云体育 Yes, will have a look at the test points of the HF PA unit Thanks Il 25/08/23 11:03, Andrew Lenton ha scritto: toggle quoted message Show quoted text The HF PA is under the main board, tricky to get to but doable 73 Get On 24 Aug 2023, at 18:56, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
Andrew Lenton All Messages By This Member #794 开云体育 They are not test points but links, you have to remove and insert an amp meter and measure the current, it is in the service manual, first check the I/P to the amp first. From memory something lile 400ma and 1 amp, the bias pots are known to fail 73 Andrew Get On 25 Aug 2023, at 21:00, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: toggle quoted message Show quoted text Yes, will have a look at the test points of the HF PA unit Thanks Il 25/08/23 11:03, Andrew Lenton ha scritto: The HF PA is under the main board, tricky to get to but doable 73 Get On 24 Aug 2023, at 18:56, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio
ik0oky All Messages By This Member #795 开云体育 Many thanks indeed Andrew, will do. 73s Emilio Il 25/08/23 22:32, Andrew Lenton ha scritto: toggle quoted message Show quoted text They are not test points but links, you have to remove and insert an amp meter and measure the current, it is in the service manual, first check the I/P to the amp first. From memory something lile 400ma and 1 amp, the bias pots are known to fail 73 Andrew Get On 25 Aug 2023, at 21:00, "ik0oky via " <yahoo.it@groups.io target=_blank>[email protected]> wrote: Yes, will have a look at the test points of the HF PA unit Thanks Il 25/08/23 11:03, Andrew Lenton ha scritto: The HF PA is under the main board, tricky to get to but doable 73 Get On 24 Aug 2023, at 18:56, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Many thanks? indeed for the hint. Will have a look at the testing procedure in the service manual Yes, 144 and 432 Mhz are fine. Regards Emilio IK0OKY Il 23/08/23 22:40, Andrew Lenton ha scritto: Ok then the PA transistors are not been driven, 100 Watts is over 20 Amps, so it is not the low pass filters. You will need to probe the HF PA, check the bias pots? are are creating the correct quesiant current, are you able to measure the input to the PA board, it should be 100 mW 73 The TX strip does have a set up procedure, and a number of test point to check I presume VHF and UHF are fine? 73 Andrew Get On 23 Aug 2023, at 19:39, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Roughly 5 A at 50 Mhz? with an unstable reading on the power supply ? Il 23/08/23 10:51, Andrew Lenton ha scritto: How much current is it drawing at full throttle Get On 22 Aug 2023, at 21:27, "ik0oky via " <yahoo.it@groups.io target=_blank>ik0oky=@groups.io> wrote: Dear FT 847 owners, after 20 + years of honest service few days ago my FT 847 started to loose output power on HF and 50/70 Mhz. Now on HF and 50/70 Mhz it delivers only less that 10 w out. I suspect some "boiled" component in the LPF bank or the final devices gone.... It has been used intensively on 50 Mhz ft8 but never at full throttle power. Any hints? for a similar experience are welcome. IK0OKY Emilio

Previous Topic Next Topic