04-02-2022, 01:36 PM
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Hello Doug
The SailMail stations normally have about 8-10 frequencies starting at 5.0 Mhz and going up to 22 Mhz. More or less the same as WinLink.
I am perplexed here because as I outline below. This install works flawlessly with the Icom M802 and the Icom AT140.
The Aerial is the back stay for the boats Mast. It is 10mm Dia, 7/19 type, 316 stainless steel wire. Each end is insulated with a special high tensile Insulator factory made specifically for that application. The length between those insulators is 57” 10”. Attached to above the lower insulator is a 10mm2 High Voltage Silicon insulated Cable 11’ 8” long which connects to a Large ceramic thru panel RF insulator. This section of cable is “stood off” the lower un-insulated section of the SS wire Back Stay with 4” stand off insulated spacers. From that thru panel insulator to the Tuner Terminal is 3’2” straight length of the same HV 10mm2 cable. That gives the 72’ 8” radiating element. All those cable connections are crimped, soldered and heat shrunk.
The RF grounds at the TX’s and the Tuners is the boat hull. At the Tuners they are Grounded by 4” copper tapes 6” long and secured with multiple SS 6 mm bolts to the rear bulkhead. This is a fully welded water tight bulkhead and so forms a intergral part of the 63’ Aluminium Hull. At the TX’s the RF ground is 4” copper tape bolted to a rib of the hull. The Aluminium hull alone is a massive ground plane, with out considering the coupling effect to the sea water and the direct connection via 6 large sacrificial anodes.
The fact that this works is that last night (Thursday 3/02 ) I made several contacts to NSW on 10 & 12 Mhz using the Icom M802 and the AT140 @ 120Watts. Also 2 contacts to Brunei on 5 & 6 Mhz. And one contact to Belgium on 16Mhz. I am located 50 Nm South of Singapore. All the time during those connections I had in line a Diamond SX200 SWR/Power meter. SWR was always less than 1.3 there were no anomalies with reflected power. I have to concluded that the Aerial and the connections to RF Ground and the connections between TX and Tuner are good. I have no visible signs of stray RF any where in electronic aboard. All the control cables are choked with Fairite Type 31 ferrites.
To alter the length of the Aerial is not all that easy. The fixed section between the Insulators cannot be altered with out major work. The only section that I could alter as a test is the 11’ 8” between the lower insulator and the Ceramic thru panel insulator. The problem with testing and substitution is that you dont know you have a issue until the SWR starts to waver. By then you have a heat damaged relay. I will make enquiries regarding the nanoVNA. Getting stuff here is frustrating. Singapore is 50 miles away but getting shipments in is a problem.
However:-
If I connect the new out of the box TS480HX and the “inflammable Tuner” into exactly that same cabling. The tuner will tune to low SWR’s all across the 3.5 to 28 Mhz range ie nothing higher than 1.4 It retains all the tune settings, it re-tunes to preset’s instantaneously. It does not show any anomalies by the Diamond SWR/Power meter or the TS480 panel SWR. I can contact and hold contacts and transact with SailMail stations. But at 150Watts, and it seems to be in the 12-18 Hz range. The Tuner will spontaneously lose tune, SWR will start to fluctuate minimally and if you do not shut it down it will burn up the Relays in that final Inductor section. In the first failure I did not realise what was happening and it destroyed 3 of the 4 relays in that final section and blew the 2 amp onboard fuse. Once I received the second replacement “inflammable Tuner” I watched it like a hawk and as soon as I saw it waver I shut it down. That still left me with a relay (K41 by the Cct diagram) that shows visible heat deformation.
This Inflammable Tuner is rated at 500Watts PEP. It is 30% physically larger than the Icom AT140 and the Relays are at least 50% larger than those that are used in the AT140.
It is both fascinating and frustrating that the $600 AT140 (rated 150 watts) can do what the $1300 500 Watt “inflammable Tuner” cannot.
Hello Doug
The SailMail stations normally have about 8-10 frequencies starting at 5.0 Mhz and going up to 22 Mhz. More or less the same as WinLink.
I am perplexed here because as I outline below. This install works flawlessly with the Icom M802 and the Icom AT140.
The Aerial is the back stay for the boats Mast. It is 10mm Dia, 7/19 type, 316 stainless steel wire. Each end is insulated with a special high tensile Insulator factory made specifically for that application. The length between those insulators is 57” 10”. Attached to above the lower insulator is a 10mm2 High Voltage Silicon insulated Cable 11’ 8” long which connects to a Large ceramic thru panel RF insulator. This section of cable is “stood off” the lower un-insulated section of the SS wire Back Stay with 4” stand off insulated spacers. From that thru panel insulator to the Tuner Terminal is 3’2” straight length of the same HV 10mm2 cable. That gives the 72’ 8” radiating element. All those cable connections are crimped, soldered and heat shrunk.
The RF grounds at the TX’s and the Tuners is the boat hull. At the Tuners they are Grounded by 4” copper tapes 6” long and secured with multiple SS 6 mm bolts to the rear bulkhead. This is a fully welded water tight bulkhead and so forms a intergral part of the 63’ Aluminium Hull. At the TX’s the RF ground is 4” copper tape bolted to a rib of the hull. The Aluminium hull alone is a massive ground plane, with out considering the coupling effect to the sea water and the direct connection via 6 large sacrificial anodes.
The fact that this works is that last night (Thursday 3/02 ) I made several contacts to NSW on 10 & 12 Mhz using the Icom M802 and the AT140 @ 120Watts. Also 2 contacts to Brunei on 5 & 6 Mhz. And one contact to Belgium on 16Mhz. I am located 50 Nm South of Singapore. All the time during those connections I had in line a Diamond SX200 SWR/Power meter. SWR was always less than 1.3 there were no anomalies with reflected power. I have to concluded that the Aerial and the connections to RF Ground and the connections between TX and Tuner are good. I have no visible signs of stray RF any where in electronic aboard. All the control cables are choked with Fairite Type 31 ferrites.
To alter the length of the Aerial is not all that easy. The fixed section between the Insulators cannot be altered with out major work. The only section that I could alter as a test is the 11’ 8” between the lower insulator and the Ceramic thru panel insulator. The problem with testing and substitution is that you dont know you have a issue until the SWR starts to waver. By then you have a heat damaged relay. I will make enquiries regarding the nanoVNA. Getting stuff here is frustrating. Singapore is 50 miles away but getting shipments in is a problem.
However:-
If I connect the new out of the box TS480HX and the “inflammable Tuner” into exactly that same cabling. The tuner will tune to low SWR’s all across the 3.5 to 28 Mhz range ie nothing higher than 1.4 It retains all the tune settings, it re-tunes to preset’s instantaneously. It does not show any anomalies by the Diamond SWR/Power meter or the TS480 panel SWR. I can contact and hold contacts and transact with SailMail stations. But at 150Watts, and it seems to be in the 12-18 Hz range. The Tuner will spontaneously lose tune, SWR will start to fluctuate minimally and if you do not shut it down it will burn up the Relays in that final Inductor section. In the first failure I did not realise what was happening and it destroyed 3 of the 4 relays in that final section and blew the 2 amp onboard fuse. Once I received the second replacement “inflammable Tuner” I watched it like a hawk and as soon as I saw it waver I shut it down. That still left me with a relay (K41 by the Cct diagram) that shows visible heat deformation.
This Inflammable Tuner is rated at 500Watts PEP. It is 30% physically larger than the Icom AT140 and the Relays are at least 50% larger than those that are used in the AT140.
It is both fascinating and frustrating that the $600 AT140 (rated 150 watts) can do what the $1300 500 Watt “inflammable Tuner” cannot.