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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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17th Apr 2020, 12:14 am | #1 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
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Very Nearly back on 80m with my old TS-530S
I’ve extracted my Kenwood TS-530S from the wardrobe for the first time in “quite a while”, and put up an 80m inverted Vee.
I have never had a “good ear” for SSB, and so I’m doing a little listening and messing around before I take to the air. The Vee is currently resonant at 3.6MHz, picking up S7 of electronic noise and the best DX heard to-date is Barcelona. I will trim the legs tomorrow. Unfortunately, the legs are not in-line, but somewhere about 135° apart. Just about the first QSO I listened to included the comment, “I use a dipole for Tx and a Wellbrook magloop for Rx”. That’s says a lot doesn’t it and I’m hoping to have my Wellgood magloop available very soon. The amp and the loop are working, just need a switchover box. The 530 seems to be working reasonably well at first glance, (TX tested in to a dummy load). The most pressing need is for a squirt of cleaner on the AF gain pot and I’ll check out one or two other “known 530 issues” shortly. Anyone else being forced back on the air ? B
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17th Apr 2020, 11:24 am | #2 |
Hexode
Join Date: Nov 2011
Location: Chippenham, Wiltshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
I commiserate. I use a TS520 and TS830 into an end-fed 84-foot inverted L with a home constructed reverse-engineered copy of the Wellbrooke loop available for receive. This loop can be rotated from the operating position.
My 'shack' is located at the end of a small garden in a Wiltshire village. There are power lines running along one boundary, the lane fronting the house is festooned with overhead telephone wires and there are numerous near neighbours. As a result, the broadband noise from the internet, SM power supplies and the like can routinely reach S7-8 Switching between the active loop and the main transmitting aerial reveals the noise environment to be highly variable over time. On the main wire, the noise can peak at S8 from Top Band to 18 MHz; it can be as low as S3. Switching to the loop always brings about an improvement in S/N ratio; received signals can gain or lose up to two S-points in absolute strength (I suppose depending on angle of arrival). On occasions, rotating the loop can bring about a steep and sharp reduction in noise; at other times, rotation has no effect at all. It seems to me that I am surrounded by multiple sources of noise, which are sometimes ‘on’ and sometimes ‘off’. My 80-metre operating periods are now largely determined by what everyone else in the locality is up to. However, the proliferation of web SDRs is a great boon - if I can just about hear the other station direct then I class that as a contact and immediately switch to Hack Green or the local Weston Kiwi site. Where there's a will there's a way! Peter G3PIJ |
17th Apr 2020, 4:27 pm | #3 | |
Dekatron
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Location: Oxfordshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
Re the magloops, what's your opinion on the importance of height above ground. There are some conflicting ideas on the net, but I could conveniently manage raising it to 10-15ft. Need to start thinking about a rotator now. Have you made any mods or component replacements on the TS's? B
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17th Apr 2020, 5:31 pm | #4 |
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Re: Very Nearly back on 80m with my old TS-530S
Magloops, No real height requirement just a bit above any metal stuff, mine is a few feet above the metal greenhouse, handy place, out of the way, not too jarring to the eye and where no plants will grow. Made my rotator from a super strong RC servo (you only need to go round 180 degrees) the power and pulse go down 100 feet of mains cable easily. Wrote a wee program to control it from the PC, also does antenna switching for the SDRs.
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17th Apr 2020, 9:50 pm | #5 | |
Hexode
Join Date: Nov 2011
Location: Chippenham, Wiltshire, UK.
Posts: 319
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
I have added an extra socket to back of the TS830 to give a separate receive aerial input. The loop power supply is connected all the time and a couple of back-to-back diodes protect the amplifier attached to the loop and also the RF amp in the transceiver. An external switch box allows selection of loop or the main aerial for receive: transmit is via the ATU and 84-foot inverted L only. Too many have blown up a Wellbrook by not having foolproof switching. Peter G3PIJ |
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18th Apr 2020, 9:18 am | #6 | |
Octode
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
Posts: 1,648
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Re: Very Nearly back on 80m with my old TS-530S
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I have been advising a friend who is trying to get his TS-520S back on the air. He's located in a 1st floor flat, but has run out a 66' long wire to a pole. That's proven untunable with his ATU so far - not surprising as its a half wave on 40m - so will have a very high impedance feed. I have suggested adding the standard 17' to convert it something like W3EDP configuration - and something close to what you are using on transmit. Can you say a bit more about your ATU, and any earthing system you have for your long wire? thanks Richard G7RVI |
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18th Apr 2020, 4:02 pm | #7 | ||
Heptode
Join Date: Mar 2008
Location: Newmarket, Suffolk, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
An 80m 1/2 wave (160m 1/4 wave) end fed was standard fare when I was first licensed in the 70s So a 1/2 wave on 40 is equally tuneable It needs a parallel tuned circuit with the antenna connected to the top and a few turns coupled to the cold end of the coil with a few turns Bog roll centres were the coil former of choice He will need to get some sort of earth, its possible as I started in a 1st floor bedroom Fourth Edition of the Rad Com handbook is very useful 73 Fred G4BWP |
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18th Apr 2020, 4:44 pm | #8 |
Octode
Join Date: Jun 2011
Location: West Midlands, UK.
Posts: 1,571
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Re: Very Nearly back on 80m with my old TS-530S
I started with an end fed wire.
https://www.americanradiohistory.com...PW-1968-05.pdf Have a look on page 31 - from our old friend FG Rayer. |
18th Apr 2020, 4:53 pm | #9 |
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Re: Very Nearly back on 80m with my old TS-530S
Some transceivers have separate RF connectors for receive only antennae. It's worth using if you have one because it does provide a bit of added protection from the odd whoopsie.
David
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18th Apr 2020, 5:16 pm | #10 | |
Hexode
Join Date: Nov 2011
Location: Chippenham, Wiltshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
The W3EDP length of 84 feet offers moderate impedance on all pre-WARC bands. I currently use a Racal auto-ATU but have previously had success with a manually-tuned pi-network. Moxon tells us that buried earth wires are a waste of time, effort and money and that the counterpoise is the way to go. My experience is that he is right - at least when it comes to my meagre resources. I use a variety of counterpoise wires strung around here and there and all brought to a single termination. The ATU is RF-isolated from earth with G3CCB bifilar toroids and the counterpoises are tuned for maximum RF with a series tapped L and variable C. I have also used the G3CCB un-un and reactance cancellation technique to good effect - see his article 'Bring back the end-fed' in the RSGB Radcom - also my article in VMARS Signal. I can attach scans of relevant bits here if you do not have access to the original text. -Peter G3PIJ |
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18th Apr 2020, 7:06 pm | #11 |
Octode
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Yes, thank you everyone for those suggestions. I am aware that a simple parallel tuned circuit, with a few coupling turns will suffice. The only objection to that is the need to actually make the thing - my friend has limited construction facilities, and limited eye sight, so unless I make it for him, that's probably not very practical.
He does have a perfectly good TenTec 227 ATU, with is a T-match. It can't tune a half-wave antenna as it stands. A 17 foot length of balanced feeder may well ease that. We will try Peter G3PIJ's suggestion of a counterpoise, and see how that goes. As with all these situations, a fair amount of experimentation is required to find something that works. Richard G7RVI |
18th Apr 2020, 9:12 pm | #12 | |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
Re the issue of adding a separate socket to an existing rig for use with a second antenna, is it the case then that the socket simply connects to the input of the RF amp via a short length of coax, leaving the existing Rx/Tx switching components in place? No that cannot work, as both antenna end up connected to the Rx input - I'm missing something? Because I need to have separate external box to enable DC to be fed down the feeder to the magloop, it occurred to me that the same unit could include a relay to switch between the transmit antenna and the Rx antenna. B
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19th Apr 2020, 9:18 am | #13 | |
Hexode
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
I can supply a diagram for the TS 830 if required. Peter G3PIJ |
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19th Apr 2020, 10:57 am | #14 | |
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
The obvious issue would be a short bit of TX power hitting the low power aerial. Less obvious is the effect of running into a changing switch on the transmitter. Valved transmitters might be OK, or it might induce a flashover in something close to ratings. It won't do the relay contacts any good as well. It's mich riskier with solid state PAs. Most modern transceivers have directional couplers, ALC, and all sorts of protection on their PAs. On pressing transmit, power is brought up as VSWR and currents are monitored. If things are too bad, the power may be throttled, or the transmit attempt aborted. So late model transmitters are thought to be protected against shorted or opened feeders... and to an extent they are. But if a feeder goes short or open during transmission, the protection stuff isn't fast enough to stop the transients created. Boom! Icom programmed their rather expensive IC-7700 transceiver to haave time delays suited to their extremely expensive solid state linear amplifier with its very fast PIN diode switching. Most people with these sets used either pre-existing linear amplifiers, or else bought other (affordable) makes with relay switching. So the transceiver's transmitter was up to power before the relays got across. Transients happened, PA and driver transistors died, very expensively. The sets got a reputation for expensive unreliability and not being covered by warranty. I saw one at Jaycee's open day a few years ago and I'd been thinking about an HF rig. The price was good, it was in perfect condition, and it did produce the right power into a dummy load. I succombed. The shipping box for these radios is huge. Scott lent me his wheeled trolley to get the thing a quarter of a mile up the street to where I was parked. On the way, dragging it up the hill, three different radio amateurs warned me "You do know those things blow PAs?" It's not a common model of radio at all, but the reputation seems so widespread. Once you know about the reason for the failures, it's easy to understand and easy to avoid. It doesn't worry me because barefoot is fine for me, I don't use or own a big amplifier. The set sits in the shack and works just fine. It goes out for special event stations where the big display and waterfall get attention. The ability to export the display to a big VGA monitor is good, too. Part way through the run of this model, Icom changed PA design from Motorola/Freescale/now-called-NXP transistors to ST ones. Mine's the Motorola era and that suits me fine as I use a lot of their parts and might be able to get a few as samples if I need any. Anyway, back to the TS530 era. That set uses 6146, I recall so it ought to be resilient, but things like early generation FT101 with 'sweep toobs' might be upset by relay switching in the RF path. I just thought a warning about the modern incarnation of a problem that is widely known, but not widely understood might save someone, somewhere a nasty bill. David
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19th Apr 2020, 4:35 pm | #15 |
Nonode
Join Date: Mar 2008
Location: Aberdeen, UK.
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Re: Very Nearly back on 80m with my old TS-530S
As David says, a thumping big aerial change over relay can save a lot of heartache Rx-wise.
Like Bazz & other lapsed 80m enthusiasts, in these troubled times, I've removed my big old Tx from under the bench where it has lain for several years, with a view to resurrecting my AM 80m rig, to be used once this last month of dry weather has ceased & I'm driven inside. Hey - what's happened to "April Showers" ? 80m AM rig - a thumping big Coastal Radio Nimbus marine band Tx & a lovely old Eddystone 730/4 Rx(well protected by the Nimbus's C/O relay). The ladder feeder to my 80m Doublet has been repaired, having re-attached several gale damaged spacers. But, I'll need those April Showers, as my earthing matrix is under the rear lawn which is very sandy & well drained. Yep, my Johnson Matchbox can change between doublet feed & long-wire centre feed/earth, but I'd like to keep both options open. The Nimbus has been happily pumping into my Marconi TF1020A/1, and its evocative to see the three 807's glowing merrily. Just think, that old Nimbus used to be sat in RNLI's Wick lifeboat over 60 years ago. When I do get back on-air I just hope that there aren't too many Russians jabbering away, or SSB enthusiasts jabbering away. That's why the rig was dismantled several years ago. But I did keep the 730/4 connected to one wire for the occasional DX-ing. Regards, David |
20th Apr 2020, 5:50 pm | #16 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
I looked for info on switching circuits on the web when I first built the magloop and some looked surprisingly simple and other somewhat more complicated.
I've asked Peter to mail me the diagram of his secondary input on the TS-830 so that I can get that clearly in view, and I've also been looking at the "accessory" socket (7 pin DIN) on the 530 to see what that has to offer in terms of voltages which could be brought in to play. B
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20th Apr 2020, 6:12 pm | #17 |
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Re: Very Nearly back on 80m with my old TS-530S
You still have to go through deciding what the timing is doing, Bazz. If you press PTT and the transmitter comes on a few milliseconds before the relay changes over, the active antenna gets enough RF voltage to ruin it even if your TX is robust enough to survive hot antenna switching.
Change over things have to be sequenced in the right order, or you wind up paying for it. Murphy dictates it won't let go until you've just found that callsign prefix you needed! David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
20th Apr 2020, 7:18 pm | #18 | |
Dekatron
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
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20th Apr 2020, 7:24 pm | #19 | |
Heptode
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
The 830 does and that gives access to the RX antenna input to connect the converted RX signal. I think the action of inserting the DIN plug switches the RX path? Might be worth looking into? Fred G4BWP |
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20th Apr 2020, 9:30 pm | #20 | |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
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Re: Very Nearly back on 80m with my old TS-530S
Quote:
then there is a socket blanked at the factory with a sticker, and then another socket labelled "REMOTE". In the manual for the 530D(?), the REMOTE socket is referred to as the 'Transceiver connection', and I need to look carefully at the connections on those to see if they are identical. At first glance, it's not clear whether there are just some inconsistent terminologies, or some real change of functions. I've got some 7-pin DINs plugs on order so that I can take a careful look at what really is on offer there. Thanks for the advice. B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. Last edited by Bazz4CQJ; 20th Apr 2020 at 9:35 pm. |
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