As far as 'limp' wire goes there are two kinds of it out there, Davis' Flexweave or ordinary stranded wire, the former has the advantages of being somewhat more flexible and is less likely to take a set that makes it difficult to coil, the latter beats the former in price and ready availability at almost any hardware store. Both can be gotten in insulated or bare form, the uninsulated wire naturally being a little more flexible as well as lighter in weight. All things considered common #18 or #20 gauge stranded wire would be more than flexible enough for the task.

KA7ENP

If you need a low profile 2m antenna that doesn't cost much you could always tape a quarter wave wire antenna to the interior of one of the car windows, either grounding it to the frame of the window or making it a 'noninverted' L with a single radial counterpoise also taped to the window. Because of the variations in window size andd the proximity of the metal around it this is very much a cut and try operation, start out with the wire considerably longer than a natural quarter wave and cut until you reach resonance. Also it would be a good idea to not use more than five or ten watts on this antenna because of RF exposure problems involved.

KA7ENP

I would say that any 9 V battery that tests out at 7.5 V under no load conditions and drops rapidly in voltage under a load is pretty much D E A D, killed by the now corrected circuit problems. Once you have replaced the battery and if the circuit still isn't operating take the electrolytic cap out of the circuit and then test the circuit, leaky electrolytic caps have caused me more problems than I can even remotely count, they are anything but reliable. Temporarily operating the circuit without the cap while testing isn't likely to hurt anything, in fact I wonder why they even put it in the circuit if it is supposed to run solely off of a battery.

I suspect in this case that replacing the dead battery will get it operational or at least much closer to it.

KA7ENP
 

Traps as a general rule ought to be enclosed in waterproof housings large enough to keep the water well away from the coil (an inch or more), otherwise wetting will produce an effect much like putting a coil within a very close fitting metal shield. Merely taping the surface or sealing it with various insulating materials will not generally suffice to completely eliminate the wet to dry trap tuning variation, something must be done to space the water away from the coil, something which fortunately is very easily done with materials that can be gotten for almost no cost at all. Secure four 2 liter plastic capped soft drink bottles, cut the bases away, drill holes in the plastic caps just big enough to admit the dipole wires, and slip them down the wires until the bottles butt together. Telescope the bottles about an inch or so, then seal the junction and where the wires emerge from the screwed down bottle caps with a noncorrosive acrylic bathtub sealant, no silicone sealant to my knowledge is truly noncorrosive to copper or copper alloys. Using some tape attach some nonconductive weights to the underside of the housings (a few ounces of wood or plastic should be plenty), then cut or punch a few small holes on the underside of the housing to drain off condensation or any small leaks that might occur in the housing, the weight serves to keep the housings from overturing and admitting rainwater. This should suffice to keep the trap from detuning significantly every time it rains.

KA7ENP

With an output voltage of 7.6 volts I'd say the regulator is toast, the output of a healthy 5 volt regulator doesn't vary more than a tenth of a volt plus or minus from its nominal value and usually much less than this. Rack it up to experience and put in a new one.

KA7ENP  

 I would suggest looking for a 5 volt bus to ground short in the decoder, in the event of a low resistance short a regulator is designed to go into its fold back current limiting mode to prevent damage to itself and to the circuit, under such conditions the voltage will typically be a volt or less.

KA7ENP

A high ambient power line generated noise level could indeed mask weaker signals and thus allow you to hear only half of the conversations, so do take the measures that you can to reduce the noise, starting with contacting your local power company about the problem. However even where ambient noise is very low or absent it is fairly common on twenty meters and the higher bands to hear only half of a conversation because of the propagation differences between the two transmitter sites, a comparatively short separation in distance between them can easily put one of the stations in a skip zone with respect to your receiving site, particularly during disturbed ionospheric conditions. I would suggest raising the 20m dipole as high as is practical in order to improve reception of the lower angle propagation that is characteristic of the higher HF frequencies, this by itself may make the once unhearable signals loud and clear. Also, it might be worth your time to erect a vertical which can be used as an alternative antenna when reception is poor on the dipole, sometimes changes in polarity can make a dramatic difference in the receivability of a signal or in noise levels.

KA7ENP

Sounds like one of the yahoos from the infamous W6NUT repeater has shown up here, there is a characteristic lack of intellect or civility in that reply to a legitimate question. Have patience, given the number of Collins afficionados here your question will soon have a proper answer.

KA7ENP

It's been quite a while since I last shopped for an HT so I'll leave the specific assessment of the latest versions up to those who have. Also, do not forget to check out the product reviews on this site, you will find them pretty much up to date and coming from the real world warts and all perspective of users. Five watts under the usual propagation conditions to be found on 2m will certainly allow you to hit the local repeaters and do some simplex work, provided that you have a fairly decent antenna (meaning something other than the rubber duckie that comes with the HT). Exact estimates as to the line of sight range five watts can attain are highly dependent on the height of the antenna above the ground, obstructions in the vicinity of the antenna, and to some extent the gain of the antenna. Height of the antenna is probably the most significant factor in making such estimates, a high antenna driven by a transmitter of low to moderate power will normally outreach a low antenna driven by a high power transmitter.

KA7ENP

On six meters you will probably notice very little or no tree attenuation, on two meters you may notice some attenuation under certain circumstances (on signals with a low S/N ratio for instance), and on 70 cm the attenuation could make your omnidirectional vertical appear to have a front to back ratio of a few dB. The estimates of tree absorption of RF below the microwave region are highly dependent on the density of the foliage, the water content of the foliage, the depth of forestation the signal has to travel through, but most of all upon rather subjective old ham's tales that tend to remarkably exaggerate the losses that can be expected. It appears that in your specific case of  just a few trees the problem will be a very minor one at worst, so if it is not possible to make use of the antenna height advantage offered by mounting an antenna in one of the offending trees the performance of the antenna on a short mast will not be noticeably different from one in the clear.

KA7ENP

The ARRL Handbook is a pretty good first volume for a homebrewer's library though it should not be the only one, some of the projects in it can be a bit daunting for a beginner. Whatever book or books you purchase it is best to start out with the simple projects first and progress to more complex ones as you gain some experience, that way the frustration factor that can come with something elaborate won't turn you off of homebrewing altogether.

KA7ENP

I think WD40 has already used a little too much of the stuff on the switch wafers between his ears, the next thing he will inquire about is likely to be the care and feeding of a 32 6LQ6 sweep tube linear on 11 meters!

KA7ENP

Sounds very like the standards used in various RSGB publications for part designators over the years are in wide use in Australia, which should not have been all that much of a surprise to me as Australia for historical and practical reasons tends to follow closely the technical conventions used in the other Commonwealth countries. The differences between US and Commonwealth standards are fortunately very minor, you are not likely to be confused very often once having dealt with an Australian schematic, they are minimal compared to the dramatic differences that can be seen between the part symbols or designators used by the electrical power industry and those used by the electronic industry in the US.

KA7ENP

Sounds like you need a simple diode clipper circuit in the headphone line (see the section of any recent ARRL Handbook pertaining to noise reduction for details) to supress the transient turn on spike. However it must be acknowledged that at higher volume levels such a simple clipper can produce an unpleasant level of audio distortion by clipping the desired signal as well as any transients, some experimentation on or adjustent of the clipper may be needed to minimize this problem. A proper soft start circuit would require some surgery on the power supply to implement and would not guarantee any reduction in the spike as sometimes such switching transients of this nature are created elsewhere than in the power supply.

KA7ENP

Ohms are universally the same unit of resistance, though alphanumeric part designators on schematics around the world can vary considerably from what we here in the USA accept as normal, even amongst the English speaking nations. As for '330R' check the R a little more closely as it may simply be a misprint K, it is sometimes surprising how many typographic errors sneak into schematic drawings to bedevil the electronic experimenter.

KA7ENP