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Ralph Mowery <rmowery28146@earthlink.net>: Dec 04 12:07PM -0500 In article <nskksftcv4c00lrjcq9i7cl4h3euv97vog@4ax.com>, jeffl@cruzio.com says... > compensate. Such a temp drop is likely when soldering large gauge > copper wire, which acts as an excellent heat sink to draw heat away > from the joint.   I went the same route. Years ago I used just the unregulated irons. Usually in the 30 to 40 watt range was recommended for solid state. They took a while to heat up. Found out they were just putting out one heat and depending on the air to limit the temperature.   When I first saw 60 and above wattage irons recommended for solid state work I thought that was way too much. However they were temperature controlled and would cut the power up and down to maintain the temperature to a much more constant heat.   I do have a big soldering gun of around 200 to 300 watts for soldering the larger stuff If I just want to make one or two quick connections on larger wiring. If more, I use a big 100 watt iron. It is not temperature controled, but the tip is about 3/8 inches in diameter and the flat part is about 1/4 inch thick. It does not cool much on the larger wire. Lots of thermal mass.   Things have changed a lot for soldering. It used to be get in quick and use heat sinks on the leads. Now the SMD uses hot air wands and you play the air over the parts for a while tuil the solder melts.

Transition Zone <mogulah@hotmail.com>: Dec 05 06:14AM -0800 On Friday, December 4, 2020 at 10:54:31 AM UTC-5, Jeff Liebermann wrote: > compensate. Such a temp drop is likely when soldering large gauge > copper wire, which acts as an excellent heat sink to draw heat away > from the joint.   The low vapor pressures of lead-tin-silver, lead-indium-silver or tin-silver solder alloys or other combinations will be different with desoldering/solder removal vacuum tools. Do they it mix it all together if resuse is needed? I've never used a vacuum for solder removal.

Transition Zone <mogulah@hotmail.com>: Dec 05 06:03AM -0800 On Wednesday, October 14, 2020 at 8:20:55 AM UTC-4, legg wrote: > Check any moving parts - switches and connector. Leave battery in, > when trying to read.   > My sympathies, but don't use anything on flash for permanent storage.   I wonder if manufacturers of late model MP3 players are security conscious enough to cause all memory to disappear once the device is opened. (Like, maybe when Apple phones are 'steamed' open).

Transition Zone <mogulah@hotmail.com>: Dec 05 05:59AM -0800 On Wednesday, December 2, 2020 at 2:57:16 PM UTC-5, Jezebels_couz wrote: > everywhere else to have a bottleneck at the end, but if all is well then > no longer concerned. There will be two 5W resistors in parallel, so > good to go on wattage. Thanks again.   Also, most current-sensing transformers don't need that high voltage (of shunt resistors) and can isolate any especially sensitive circuitry that might be there.

liz@poppyrecords.invalid.invalid (Liz Tuddenham): Dec 04 04:48PM > good. It is not just one ham receiver,but several.   > My theory is that the portable receiver is matched for a high impedance > short antenna, where the ham receiver is matched for a 50 ohm antenna.   Yes, that would account for it. The portable might connect the aerial to a tuned circuit so the termination is optimally matched for both resistance and reactance across the bands.   -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk

Ralph Mowery <rmowery28146@earthlink.net>: Dec 04 11:55AM -0500 In article <ljnksf9k53i46g4i1s0hvpq4a41sgl6f58@4ax.com>, ken1943 @invalid.net says...   > Amateur Radio equipment is built to favor ham frequencies and not > broad banded like your general equipment.   I know that, however my ham transceivers check out very well on most all frequencies.   However the portable picks up the hams with just the whip, where with wire the same length or even longer the ham transceivers picks up almost nothing. Checking them out on a service monitor, they are sensitive enough. However when the ham gear is used with a antenna only a few feet long tuned to frequency in a car they pick up lots of signals.

Clifford Heath <no.spam@please.net>: Dec 05 08:22AM +1100 On 5/12/20 3:00 am, Ralph Mowery wrote: > receives almost nothing. > My theory is that the portable receiver is matched for a high impedance > short antenna, where the ham receiver is matched for a 50 ohm antenna.   Your portable probably has a ferrite loopstick in it also.

dplatt@coop.radagast.org (Dave Platt): Dec 04 02:46PM -0800 In article <MPG.3a3434126dcf9e0a98a0c4@news.east.earthlink.net>, >nothing. Checking them out on a service monitor, they are sensitive >enough. However when the ham gear is used with a antenna only a few >feet long tuned to frequency in a car they pick up lots of signals.   I suspect that your guess about impedance matching is probably "on the mark". Since the ham transceiver is normally hooked up to a 50-ohm (or so) trqansmission line, it's probably designed to terminate the incoming signal into 50 ohms or thereabouts when it's in receive mode.   If you hook a short wire to it, the short wire is going to have a very high (and very capacitive) impedance. The 50-ohm termination will look very much like a short-to-ground compared to that high impedance, and there will only be a trace of signal left for the receiver to detect.   A short-wave receiver is designed to work with a short antenna (wire or whip). The antenna is a lot shorter than a wavelength, and so there's no real need to terminate it into a matched impedance. The short-wave receiver can use a high-impedance receiving circuit (e.g. a JFET) and doesn't lose signal into an inappropriately-low termination impedance.   Some ham transceivers have a separate "receive antenna" jack - the Kenwood TS-2000 has one. These may be high-impedance inputs suitable for a wire or whip, or they might be 50-ohm antennas.   If you were to provide a small battery-powered buffer for your random wire (say, a J310 JFET set up as a source follower) you could reduce the effects of the mismatch and you'd probably find your transceiver able to receive quite nicely.

Brian Gregory <void-invalid-dead-dontuse@email.invalid>: Dec 05 12:31AM On 04/12/2020 21:22, Clifford Heath wrote: > Your portable probably has a ferrite loopstick in  it also.   Probably not for shortwave though.   -- Brian Gregory (in England).

bilou <bilou@sfr.fr>: Dec 05 10:46AM +0100 On 04/12/2020 17:00, Ralph Mowery wrote: > good. It is not just one ham receiver,but several.   > My theory is that the portable receiver is matched for a high impedance > short antenna, where the ham receiver is matched for a 50 ohm antenna.   Your theory is absolutely correct :-) A good example is the AM band car radio. The great advantage of low impedance is that it is well suited to coaxial cables. In car radios there was an adjustable capacitor to compensate for the short length of the cable and front end tuning was good only on the station selected.

Transition Zone <mogulah@hotmail.com>: Dec 04 10:36AM -0800 On Monday, November 30, 2020 at 7:40:03 AM UTC-5, Frank wrote in alt.home.repair: > that smoke detectors are recommended to be replaced by 10 years. Still > not sure a combo appeals to me since I got over 20 years out of two > smoke detectors before I replaced them. Its easy to forget and just leave the detector in place.

"ohg...@gmail.com" <ohger1s@gmail.com>: Dec 04 09:32AM -0800 I have a McIntosh MX110Z with a bad transformer. Any recommendations for rewinding? I've never done one and have no interest in trying. Thanks.

"Peter W." <peterwieck33@gmail.com>: Dec 04 10:09AM -0800 > I have a McIntosh MX110Z with a bad transformer. Any recommendations for rewinding? I've never done one and have no interest in trying. Thanks.   https://www.mercurymagnetics.com/brands/mercury-vintage-transformer-restoration-service/   And there is the Mother Ship, McIntosh itself.   Peter Wieck Melrose Park, PA

"ohg...@gmail.com" <ohger1s@gmail.com>: Dec 04 10:35AM -0800 On Friday, December 4, 2020 at 1:09:55 PM UTC-5, Peter W. wrote:   > And there is the Mother Ship, McIntosh itself.   > Peter Wieck > Melrose Park, PA   I did take the long shot and emailed McIntosh directly. I haven't heard back from them yet, but I assume given the age of this tuner/pre, they won't be of much help.

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