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Search: Posts Made By: llonen
Forum: General Electronics Technical Discussion 10-08-2018, 03:29 AM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Sorry this has been bugging me for a while and I have only just had the inclination to revisit it, their schoolboy error here in the way the measurement is being made, well for one your seeing a peak...
Forum: General Electronics Technical Discussion 10-03-2018, 04:30 PM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

With the waveform I am feeding into the coil actuator, that being a square wave the resultant switching waveform consisting of a dc 12 supply limited to 100ma or 500ma should look within the limits...
Forum: Equipment Usage, Soldering, Techniques, and Reviews 10-03-2018, 11:35 AM
Replies: 18
Views: 459
Posted By llonen
Re: What are the minimal devices needed to do the most usual electronic repairs?

I have been running a repair service successfully for quite some years now, my work day can be anything from tumble dryers / washing machines to macbook pro's and lots in between I do avoid mobile...
Forum: General Electronics Technical Discussion 10-03-2018, 09:54 AM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

And of course not to forget some of the dross, I had 15 final pulls from 10 boards, some tested completely welded closed and some were completely open. the rest tested as intermittent but showed as...
Forum: General Electronics Technical Discussion 10-03-2018, 09:49 AM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

So here we are then, having worked my way through 10 of these hobart bar aid boards here are some of the resultant relay failures.

So first the test layout, then a good control sample then a...
Forum: General Electronics Technical Discussion 09-27-2018, 03:26 AM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

Well I could test at a much higher current as the relay contacts are rated at 5amp 30 volts, the object though is not a destructive or damaging test rather to assess contact quality and bounce which...
Forum: General Electronics Technical Discussion 09-26-2018, 03:09 PM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

I have come into the workshop 10 Baraid controller boards with a large number of relays on each for testing, so I looked into the way I was testing them again and came up with a 'simpler' method. I...
Forum: General Electronics Technical Discussion 09-14-2018, 05:33 AM
Replies: 5
Views: 183
Posted By llonen
Re: Importance of wicking during rework?

Always remove as much of the remaining solder for bga rework, come to think of it for rework really, SMD or otherwise although I make use of a pace solder extractor for through hole plated stuff and...
Forum: General Electronics Technical Discussion 09-11-2018, 06:15 PM
Replies: 8
Views: 356
Posted By llonen
Re: QFP128 desoldering / rework question

Right you are looking for commercial solders that contain the following

51%In / 32.5%Bi / 16.5%Sn (60C eutectic)
66.3%In / 33.7%Bi (72C eutectic)
57%Bi / 26%In / 17%Sn (79C eutectic)
54%Bi...
Forum: General Electronics Technical Discussion 09-10-2018, 01:09 AM
Replies: 8
Views: 356
Posted By llonen
Re: QFP128 desoldering / rework question

I used to use a generic low melting point solder which was the same as quick chip, which I purchased by the roll until I invested in a half decent hot air rework station (Hako FR802) when I am back...
Forum: General Electronics Technical Discussion 09-05-2018, 05:40 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Well your seeing 40 volts Peak to Peak which is entirely consistent with 4 the four watts I'm suspecting your HT is developing, if you were getting a Peak value or RMS value of 40 volts then as above...
Forum: General Electronics Technical Discussion 09-03-2018, 12:43 AM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

There seems to be an oddity with the way I arrived at the values in my last post (it was 2am in the morning) anyways I have just setup on the bench a 2.5 watt 50mhz signal from a FT690 as I don't...
Forum: General Electronics Technical Discussion 09-02-2018, 06:57 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

If you are getting around 40 volts on the scope, assuming you have everything setup correctly and you are reading from the waveform peak to peak I would say your measurement sounds about right, I...
Forum: General Electronics Technical Discussion 09-02-2018, 06:13 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Unless I am missing something obvious, you've done the maths and that agrees with the table, are you getting the 40 odd volts from the scoped waveform ?
Forum: General Electronics Technical Discussion 09-02-2018, 04:30 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Regarding DBm volts and watts

Using a 50 ohm system you could expect the following

14.1 volts 4 watts
22.4 volts 10 watts
44.6 volts 40 watts etc

These were un-ashamedly lifted from...
Forum: General Electronics Technical Discussion 09-01-2018, 09:47 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Well you should be good to go then, check the power handling of the 50 ohm termination but I suspect you will still need something like a 10:1 ratio through line attenuator, if this is a hand held...
Forum: General Electronics Technical Discussion 09-01-2018, 04:38 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Most scopes that I know of are high impedance, unless you are referring to a spectrum analyser which often have input impedance's of either 50 or 75 ohm. Usually the input is limited to a few watts...
Forum: General Electronics Technical Discussion 08-29-2018, 05:51 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

While it is entirely possibly to measure feed voltage and convert to watts based upon a 50 ohm impedance you will need a calibrated RF probe for this. I used this method for quite some time before...
Forum: General Electronics Technical Discussion 08-28-2018, 04:47 PM
Replies: 31
Views: 609
Posted By llonen
Re: "overvolting" transmitters for more power

Well you might want to connect this to a dissipative 50 ohm load and see what RF power you are actually developing, that said what make and model number is this as some handheld radios were designed...
Forum: Troubleshooting Game Consoles & Other Weird Devices 08-20-2018, 02:35 PM
Replies: 18
Views: 351
Posted By llonen
Re: Amiga 600 PCB corrosion from capacitors leaking electrolyte

I have used both with good success in the past, but for commercial repairs given the extent of the damage to the pads and some of the traces if this was a repair job I was working on the pads and...
Forum: General Electronics Technical Discussion 08-20-2018, 09:33 AM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

Mainly I look for degraded contacts which shows up really well on a scope tells me more than measuring the contact resistance itself as this can vary significantly from throw to throw. Essentially...
Forum: General Electronics Technical Discussion 08-18-2018, 08:02 PM
Replies: 20
Views: 796
Posted By llonen
Re: how to automate relay testing

I use an oscilloscope and a simple octopus circuit for testing relays, allows me to look at contact quality at varying rates and loads. I will post some details when I get back to the workshop.
Forum: General Computer Discussion 08-18-2018, 07:49 PM
Replies: 14
Views: 304
Posted By llonen
Re: Server as video/3D editing station...feasible ?

I have been using Xeon based servers for workstations for long time now for precisely that reason 'costing' cant say I have had any problems with drivers etc for them.
Forum: Troubleshooting Game Consoles & Other Weird Devices 07-21-2018, 07:12 PM
Replies: 26
Views: 543
Posted By llonen
Re: Belcom LS120l radio (crystal filter)

I can put up a pic of the whole board(s) of which there are several, the unit is not a Uniden chassis and includes quite a lot of discreet logic on one of the boards. It is however a very easy mod...
Forum: Equipment Usage, Soldering, Techniques, and Reviews 07-04-2018, 05:54 PM
Replies: 7
Views: 270
Posted By llonen
Re: Looking for a new rework solder station

When I get back to the Lab tomorrow I will put up a more complete list if it is any use to you.
Showing results 1 to 25 of 259

 
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