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general question re polarized ac plugs on receivers as shipped originally
just wondering: were any Halli receivers shipped with polarized 2 or 3 prong AC plugs, and if so which models or when.
is/was there any? evidence? not speculation? It is hard to answer for sure now, since most cords have been changed a some time for one reason or the other. 73? don VA3DRL |
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Re: S-40B - What is the socket on the back for?
On Mon, Jan 9, 2023 at 04:00 AM, Craig Delmage wrote:
Thanks Steve - that explains the connector mystery. The plate on my second radio is sure ugly. They should have just popped in a connector....then would that spot work to mount a fuse holder?? Might even look better than that plate? ps...I have at least two s-40's stored for future investigation, one at least has some mysterious variations.. so i am collecting what-to-do hints. 73 --don? VA3DRL |
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Re: SR-400 Cyclone VOX problem
¿ªÔÆÌåÓýI think your relay is ok. I believe your problem is
on the grid side of V20B. I would not "tinker" with the values. Between the HT44, cyclone, cycloneII and the cycloneIII this same basic circuit is out there working perfectly in thousands of radios. There is a faulty part somewhere. The original factory spec
on the relay coil is 9K +- .5K. I have seen them as high as 14K and still work to spec.
Info on the vox relay
?Walt Cates,
WD0GOF
?
Your past has no control over your future. Only your NOW can impact your future.
From: [email protected] <[email protected]> on behalf of JThorusen <jthorusen@...>
Sent: Sunday, January 8, 2023 4:14 PM To: [email protected] <[email protected]> Subject: [HallicraftersRadios] SR-400 Cyclone VOX problem ?
Greetings to the Group:
I am trying to put the finishing touches on an SR-400 Cyclone transceiver.?? I have run into a problem with the VOX, however.?? The Vox Delay when set to minimum is about 1 second, which is a bit long.?? Any significant increase in the delay pot setting from full CCW results in infinite delay.?? R156 (6.8 meg) and R154 (1 meg) have been replaced with new 1% parts.?? R157 (3.3 meg) has been replaced with a new 5% part.?? The 10 meg VOX delay pot is made of unobtanium, so I hope that is not the problem; it should be out of the circuit when set full CCW, yet the delay is still too long. I had difficulties with K2 hanging up on PTT.?? After measuring some voltages around the Relay Amp (V20) I came to the conclusion that the tube was biased normally and that the residual plate current was reasonable based on the EbIb curves in a tube manual for the 12AT7.?? Accordingly, I shortened the spring in the relay.?? This cured the PTT problem, but the VOX problem persists.?? I note that the voltage across the relay decays fairly quickly to about 9 volts when microphone input stops, but it takes a bit more time to decay to 8 volts which is the quiescent point.?? Shortening the spring further has not helped the relay drop-out time.?? Touching a DVM probe to the V20 grid (pin 2) would cause the relay to drop before I tampered with the spring, although I have not repeated that experiment. The relay has 10.26 K ohms coil resistance.?? With 8 volts across it, the current is only .779 mA or 779 microamps.?? With 9 volts across the relay, the coil current is still less than 1 mA; it is .877 mA or 877 microamps.?? Eight or nine volts should not be enough to hold up a relay rated for 110 VDC, but it is apparently almost enough.?? With over 250 volts of plate volts on the 12AT7, the tube manual curves suggest that the above currents are normal for a -6 volt grid voltage which is what I have; the grid (pin 2) is at 0 volts while the cathode is at +6 (manual says 5.5).?? So, the relay may be part of it, but it seems that the grid of the 12AT7 is simply too high an impedance to allow the VOX control voltage to bleed off in a timely fashion.?? Rather than tinker with the values in the circuit to reduce the delay time, I thought I would ask here to see if anyone has any suggestions concerning this problem. BTW, I attempted to order a couple of relays from the 'bay, but the seller refunded my money saying he was out of stock.?? There is another seller there with relays at about 3 times the price, which I suppose I could do if necessary, but I don't think that will solve the delay time problem.?? The Potter & Brumfield part number is KHP 17 D 11, 110 VDC.?? The Hallicrafters part number is 021-000732.?? If anyone has one for less than the $40 or so that I would have to pay on evilbay, I would be interested. Thanks for any suggestions or thoughts. -- Jim T. KB6GM |
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Re: SR-400 Cyclone VOX problem
¿ªÔÆÌåÓý
Happy new year Jim,
Check the static condition of V20A/B per chart below.
?Walt Cates,
WD0GOF
?
Your past has no control over your future. Only your NOW can impact your future.
From: [email protected] <[email protected]> on behalf of JThorusen <jthorusen@...>
Sent: Sunday, January 8, 2023 4:14 PM To: [email protected] <[email protected]> Subject: [HallicraftersRadios] SR-400 Cyclone VOX problem ?
Greetings to the Group:
I am trying to put the finishing touches on an SR-400 Cyclone transceiver.?? I have run into a problem with the VOX, however.?? The Vox Delay when set to minimum is about 1 second, which is a bit long.?? Any significant increase in the delay pot setting from full CCW results in infinite delay.?? R156 (6.8 meg) and R154 (1 meg) have been replaced with new 1% parts.?? R157 (3.3 meg) has been replaced with a new 5% part.?? The 10 meg VOX delay pot is made of unobtanium, so I hope that is not the problem; it should be out of the circuit when set full CCW, yet the delay is still too long. I had difficulties with K2 hanging up on PTT.?? After measuring some voltages around the Relay Amp (V20) I came to the conclusion that the tube was biased normally and that the residual plate current was reasonable based on the EbIb curves in a tube manual for the 12AT7.?? Accordingly, I shortened the spring in the relay.?? This cured the PTT problem, but the VOX problem persists.?? I note that the voltage across the relay decays fairly quickly to about 9 volts when microphone input stops, but it takes a bit more time to decay to 8 volts which is the quiescent point.?? Shortening the spring further has not helped the relay drop-out time.?? Touching a DVM probe to the V20 grid (pin 2) would cause the relay to drop before I tampered with the spring, although I have not repeated that experiment. The relay has 10.26 K ohms coil resistance.?? With 8 volts across it, the current is only .779 mA or 779 microamps.?? With 9 volts across the relay, the coil current is still less than 1 mA; it is .877 mA or 877 microamps.?? Eight or nine volts should not be enough to hold up a relay rated for 110 VDC, but it is apparently almost enough.?? With over 250 volts of plate volts on the 12AT7, the tube manual curves suggest that the above currents are normal for a -6 volt grid voltage which is what I have; the grid (pin 2) is at 0 volts while the cathode is at +6 (manual says 5.5).?? So, the relay may be part of it, but it seems that the grid of the 12AT7 is simply too high an impedance to allow the VOX control voltage to bleed off in a timely fashion.?? Rather than tinker with the values in the circuit to reduce the delay time, I thought I would ask here to see if anyone has any suggestions concerning this problem. BTW, I attempted to order a couple of relays from the 'bay, but the seller refunded my money saying he was out of stock.?? There is another seller there with relays at about 3 times the price, which I suppose I could do if necessary, but I don't think that will solve the delay time problem.?? The Potter & Brumfield part number is KHP 17 D 11, 110 VDC.?? The Hallicrafters part number is 021-000732.?? If anyone has one for less than the $40 or so that I would have to pay on evilbay, I would be interested. Thanks for any suggestions or thoughts. -- Jim T. KB6GM |
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Re: soldering station
On Sat, Jan 7, 2023 at 06:08 PM, Jim Pruitt wrote:
What tips does the Edsyn 951 use?? I have one new in the box that I bought about 15 years ago but never even opened the box.? I have up until recently always used my Weller WTCPT and TC201 with a 1/64" tip and use that for pc boards and boat anchors.? I recently (last week) bought a Hakko FX888 but it was a dud.? Actually it was ok with the T18-C tip that came with it but I also bought 2 of the T18-BL (long 1/64" needle tips) and yes they were in Hakko packages and brand new never opened but the FX888 would not heat the tip!? At the back I measured just 101¡ã and at the tip it was 86¡ã and most of the time would not melt solder at all and I had it set to 750¡ã and later to 800¡ã as my Weller always used the 800 degree tips.? So I have been looking for a good soldering station.? I have several Chinese clones and find them to be worthless (at least all that I have bought).? I also bout a couple that had the solder sucker gun on them.? One was the ZD915 which worked well the first week but now just does not do the job.? I later bought a Aoyue 701A++ but that sucker gun does not work at all and I can not get tips that are big enough.? The tip has to go over the thing being desolder so a switch terminal will not desolder but a wire will!? Neither the ZD915 or the Aoyue offered big tips (opening at the end so it would go over a terminal) and now getting 701A++ tips is near impossible and it is not that old.?sounds like you might be in the Bermuda triangle!! or a destructive tester? or just bad luck ? hope you get a working setup. 73 don VA3DRL |
don Root
waltcates