Discussion:
Thruline Wattmeters x5 plus elements
(too old to reply)
p***@rsconnect.com
2018-03-07 10:27:28 UTC
Permalink
Hi guys,

I have 5 Thruline wattmetters by the Bird Electronic Corporation I'd like to sell or at least find out their true worth.

I've seen a few at some good prices on eBay which is where I'd prefer to advertise them but as they're new to me and YouTube doesn't give the best tutorials on how to test them.

Hopefully I'm in the right place for a bit of advice of maybe even an offer.


Thank you
Brian Reay
2018-03-07 11:48:08 UTC
Permalink
Post by p***@rsconnect.com
Hi guys,
I have 5 Thruline wattmetters by the Bird Electronic Corporation I'd like to sell or at least find out their true worth.
I've seen a few at some good prices on eBay which is where I'd prefer to advertise them but as they're new to me and YouTube doesn't give the best tutorials on how to test them.
Hopefully I'm in the right place for a bit of advice of maybe even an offer.
Thank you
It depends on the model.

The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.

With the PEP function, £150 +

Elements, typically £30 each.

If you've got clean one in a case with a good selection of elements, you
may get a better price.

As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them against
another meter.

At one time, Bird meters were considered the 'gold standard' but, these
days, people tend to buy one of the Japanese meters. I may be worth
trying one of the more specialist groups frequented by the homebrew types.
Spike
2018-03-07 12:54:21 UTC
Permalink
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements, you
may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them against
another meter.
At one time, Bird meters were considered the 'gold standard' but, these
days, people tend to buy one of the Japanese meters. I may be worth
trying one of the more specialist groups frequented by the homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
--
Spike

"RSGBTech is meant for everyone", or so the RSGB says. The group is
moderated 'to
ensure that the questions are on topic', but the group's own admissions
policy mention
(a pre-) 'vet', 'known', 'trouble', and 'maker', but not the vetting
policy! None of these are
'moderation' issues and none are mentioned in the RSGB's Guidelines.....
Stephen Thomas Troll
2018-03-07 13:00:13 UTC
Permalink
Post by Spike
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
Burt, sing us a song about The Waves, Burt. Burt, sing it in a language
that only you understand, Burt.


Burt, Thanks, Burt.
--
Visit Derbyshire's 2nd biggest supplier of Bullshit:
http://jprfarmdirect.co.uk
===
Obsessed with someone in North Kent?
Feeling inferior due to being a lying halfwit?
Fed up of being laughed at due to your badly thought out lies?
Then post the same old shit to Usenet day-after-day-after-day...
Ian Jackson
2018-03-07 13:55:53 UTC
Permalink
Post by Spike
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements,
you may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them against
another meter.
At one time, Bird meters were considered the 'gold standard' but,
these days, people tend to buy one of the Japanese meters. I may be
worth trying one of the more specialist groups frequented by the
homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
A REAL Class-A could probably get nearly as close by judging the
severity of the RF burn that he gets when he touches the croc-clip
attaching the aerial to the ATU coil.
--
Ian
Brian Howie
2018-03-07 14:04:35 UTC
Permalink
Post by Spike
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements,
you may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them against
another meter.
At one time, Bird meters were considered the 'gold standard' but,
these days, people tend to buy one of the Japanese meters. I may be
worth trying one of the more specialist groups frequented by the
homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
Tungsten lightbulbs have extremely nonlinear resistance with temperature
and hence input power. I thought of usinge a 100W 240 V one as load for
a Rhombic, as near enough 600ohm but the resistance would vary too much.
On SSB, the F/B ratio would have depended on talk level.

Some sort of calorimeter using temperature rise of a fluid immersed
resistor might be better. I've never seem anything in the ham radio
literature though; someone must have done it. It's an easy way to test
the output of microwave ovens.

Brian
Spike
2018-03-07 17:29:55 UTC
Permalink
Post by Spike
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements,
you may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them
against another meter.
At one time, Bird meters were considered the 'gold standard' but,
these days, people tend to buy one of the Japanese meters. I may be
worth trying one of the more specialist groups frequented by the
homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
Tungsten light bulbs have extremely non-linear resistance with temperature
and hence input power.  I thought of using a 100W 240 V one as load for > a Rhombic, as near enough 600ohm but the resistance would vary too much.
On SSB, the F/B ratio would have depended on talk level.
Tut tut!

As a Class A, I wouldn't rely on such a non-linear device on its own for
the power measurement, which is why I specified two bulbs (and some bits
and pieces) in a 'null method' system.
Some sort of calorimeter using temperature rise of a fluid immersed
resistor might be better. I've never seem anything in the ham radio
literature though; someone must have done it. It's an easy way to test
the output of microwave ovens.
A 50 ohm resistor in a tin of oil would be the sort of thing you're
thinking of, I suspect.
--
Spike

"RSGBTech is meant for everyone", or so the RSGB says. The group is
moderated 'to
ensure that the questions are on topic', but the group's own admissions
policy mention
(a pre-) 'vet', 'known', 'trouble', and 'maker', but not the vetting
policy! None of these are
'moderation' issues and none are mentioned in the RSGB's Guidelines.....
g***@gmail.com
2018-05-30 19:29:01 UTC
Permalink
Post by Spike
Post by Spike
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements,
you may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them
against another meter.
At one time, Bird meters were considered the 'gold standard' but,
these days, people tend to buy one of the Japanese meters. I may be
worth trying one of the more specialist groups frequented by the
homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
Tungsten light bulbs have extremely non-linear resistance with temperature
and hence input power.  I thought of using a 100W 240 V one as load for > a Rhombic, as near enough 600ohm but the resistance would vary too much.
On SSB, the F/B ratio would have depended on talk level.
Tut tut!
As a Class A, I wouldn't rely on such a non-linear device on its own for
the power measurement, which is why I specified two bulbs (and some bits
and pieces) in a 'null method' system.
Some sort of calorimeter using temperature rise of a fluid immersed
resistor might be better. I've never seem anything in the ham radio
literature though; someone must have done it. It's an easy way to test
the output of microwave ovens.
A 50 ohm resistor in a tin of oil would be the sort of thing you're
thinking of, I suspect.
For the bulb thing, you'd need a Z-match (or auto tuner) so that the tx sees 50ohm at all the power settings .OK not impossible. They eye is pretty good at relative brighteness ± 1db at a guess.

Yes oil or some other fluid. Calorimeter with a thermometer and a timer would be the most accurate and you could calibrate it using DC.

I've done it the other way round using a resistor and boiling water and iced water to do NF measurements.

Brian

Roger Hayter
2018-03-07 19:14:24 UTC
Permalink
Post by Spike
Post by Brian Reay
I have 5 Thruline watt-meters by the Bird Electronic Corporation I'd
like to sell or at least find out their true worth.
It depends on the model.
The basic ones, without the PEP function, tend to go for perhaps
£100-£125 depending on condition.
With the PEP function, £150 +
Elements, typically £30 each.
If you've got clean one in a case with a good selection of elements, you
may get a better price.
As for testing, they tend to be pretty tough. I'd suggest just trying
them on a radio which you know the power of and, if they seem to be
within 10%, they should be OK- assuming you can't compare them against
another meter.
At one time, Bird meters were considered the 'gold standard' but, these
days, people tend to buy one of the Japanese meters. I may be worth
trying one of the more specialist groups frequented by the homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
More like -50/+100% precision I would think!
--
Roger Hayter
Spike
2018-03-08 08:50:52 UTC
Permalink
Post by Roger Hayter
Post by Spike
Post by Brian Reay
At one time, Bird meters were considered the 'gold standard' but, these
days, people tend to buy one of the Japanese meters. I may be worth
trying one of the more specialist groups frequented by the homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
More like -50/+100% precision I would think!
Not strong on physics, are you!
--
Spike

"RSGBTech is meant for everyone", or so the RSGB says. The group is
moderated 'to
ensure that the questions are on topic', but the group's own admissions
policy mention
(a pre-) 'vet', 'known', 'trouble', and 'maker', but not the vetting
policy! None of these are
'moderation' issues and none are mentioned in the RSGB's Guidelines.....
Stephen Thomas Cole
2018-03-08 09:58:26 UTC
Permalink
Post by Spike
Post by Roger Hayter
Post by Spike
Post by Brian Reay
At one time, Bird meters were considered the 'gold standard' but, these
days, people tend to buy one of the Japanese meters. I may be worth
trying one of the more specialist groups frequented by the homebrew types.
A Class A could probably get within 10 percent by using a couple of
light bulbs, a sheet of paper, and some minor bits and pieces. Class
B/M3 types seem to need expensive equipment to get a similar result.
More like -50/+100% precision I would think!
Not strong on physics, are you!
Waves, Burt. Fucking waves! YFI.
--
STC / M0TEY /
http://twitter.com/ukradioamateur
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