More Chinese how to get rid of tiny ants in the house AM radio kits – Page 7 – UK Vintage Radio Repair and Restoration Discussion Forum

Firstly the supply current to the audio & driver stages and the whole radio. At least one check with a 1khz sine wave and how to get rid of tiny ants in the house audio into a dummy load, to check that the audio stages are basically distortion free how to get rid of tiny ants in the house and have around the correct output level.

Then a sweep of the IF (ideally with a signal generator and scope) to ensure the IF is stable, has about the correct bandwidth & gain.(if not the bypass and grounding arrangements and AGC system how to get rid of tiny ants in the house checked and modified if required) then a check of the local oscillator level and frequency how to get rid of tiny ants in the house range. Then an overall radio sensitivity check.

There are a lot of variables which could sabotage the how to get rid of tiny ants in the house operation and performance of the radio kit, so these checks, on a newly built unit, are definitely required. If they are not done you end up with all how to get rid of tiny ants in the house the reports of bad performance or failure to operate, many a case it will just be one unsuitable part how to get rid of tiny ants in the house or component or something simple. Without the systematic tests, the faults will remain unsolved and elusive. A lot of the time you can "get lucky" and everything will appear to be ok first pop, but as shown by the remarks on this thread, it is a bit hit & miss.

I decided to have a go at making one of how to get rid of tiny ants in the house these radios, bought from a singapore site as it was under £5 including postage and arrived quite quickly. It went together reasonably well, the red plastic aerial ferrite holder needed one screw hole how to get rid of tiny ants in the house countersinking as the screw wouldn’t go into the tuner even after the edge was how to get rid of tiny ants in the house bevelled as it was hitting a couple of the solder how to get rid of tiny ants in the house joints and wouldn’t lay flat. I tried a diode instead of the 9018G transistor as how to get rid of tiny ants in the house the detector, a BA219 as it was the only one I had, a 1N916 should also work here. Because the agc is taken from the anode of the how to get rid of tiny ants in the house diode via the last IF secondary the cathode connects to how to get rid of tiny ants in the house the volume control end, unlike a conventional pocket radio with npn transistors where the how to get rid of tiny ants in the house cathode connects to the last IF transformer.

The radio has only been temporary put together along with how to get rid of tiny ants in the house a temporary speaker to try it, and it worked straight away. Only the oscillator trimmer, the one nearest the edge of the case on the how to get rid of tiny ants in the house tuner, needed some adjustment to get the stations in roughly the how to get rid of tiny ants in the house right place, this will be improved once the dial is fitted. It still needs some final putting together but I am how to get rid of tiny ants in the house tempted to leave the speaker as it sounds very good, it was quite a revelation as I wasn’t really expecting it to work all that well if how to get rid of tiny ants in the house at all. The quiescent current is around 20ma so would like to how to get rid of tiny ants in the house get this down a bit, possibly a larger value of base bias resistor or the how to get rid of tiny ants in the house output transistors emitter resistor added.

The 9018G transistors give plenty of gain in the IF how to get rid of tiny ants in the house stage, the IF transformers are spot on. The only components I used from my own parts was how to get rid of tiny ants in the house a 100uf capacitor instead of the one of the two how to get rid of tiny ants in the house supplied, and the 0.01uF mixer input coupling capacitor as, like others here, it was the only part missing. Orange sleeving was used on the resistor leads but they how to get rid of tiny ants in the house are so thin the sleeving wouldn’t go around the curved part. The gaps in the printed board for current measuring had how to get rid of tiny ants in the house wire from the offcuts soldered across rather than just solder how to get rid of tiny ants in the house to bridge them.

The doubtful components were the capacitors as others have found how to get rid of tiny ants in the house – the electrolytics all had ESR’s which were a little high, and the disc ceramics were out of spec, even applying the worst case tolerance of +80% -20%. I sourced suitable replacements from my stock.

The supplied transistors were 4x 9018G and 3x9013h, so no 9018H for V3, V4 and V5, again something which others seemed to have experienced. However the gain figure for the transistors was within that how to get rid of tiny ants in the house specified, so I decided to use them in the kit, using the highest gain 9018G for V1, and close matched 9013H’s for the output pair V6 and V7. The diodes are all 1N4148 as supplied, and tested ok.

The kit went together well and once completed was powered how to get rid of tiny ants in the house and tested with a DMM across the five bridging points. All measurements agreed with the values shown on the schematic. The bridging points were then soldered with a wire link, and everything assembled into the case.

Switch-on resulted in a speaker hiss and tuning brought in how to get rid of tiny ants in the house a few stations. The frequency was a little high against the tuning scale, but adjustment of the ferrite rod antenna/coupling coil position, trimmer capacitors and oscillator transformer corrected that. The IF transformers were peaked for maximum audio output. I was surprised by the level of audio output – given a 3 volt supply voltage, and the sound quality was very acceptable from the tiny how to get rid of tiny ants in the house loudspeaker. Altogether very pleasing for a £5 investment.

HX108-2. Have built two of these. With the first one I messed up and got an how to get rid of tiny ants in the house output transistor the wrong way round which explained the awful how to get rid of tiny ants in the house distortion. After correcting my mistake the sound quality was no better how to get rid of tiny ants in the house so maybe the transistor was fried. The second one had a damaged speaker so I swapped how to get rid of tiny ants in the house it with the other one. Works quite well but sound quality still not great.

S66E. Have built three but only paid for one (long story). All work surprisingly well and sound is better than expected how to get rid of tiny ants in the house from the plastic speaker. Headphone socket is a bonus although the hole in the how to get rid of tiny ants in the house case doesn’t line up with the PCB. As an experiment I built one of them with closer how to get rid of tiny ants in the house tolerance resistors and caps. Result: no noticeable difference.

210SP ‘paeansonic’. Good FM performance but AM very weak. Stiff tuning due to the horrible dial pointer method. Locks onto FM stations well, clean, clear sound from the tiny plastic speaker. Awkward to tweak as the batteries come out when you how to get rid of tiny ants in the house take the back off.

ZX620 AM/FM in an ugly yellow case. The actual radio I received from banggood was the AM/SW version ZX623 and got a full refund. SW is one band 15M, not very useful. AM performance is excellent as is the sound quality from how to get rid of tiny ants in the house the ‘large’ real speaker. I can quite happily live with this one, just a shame that’s there’s no FM. It appears that the ZX620 is no longer available.

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