Date   
Re: I'm hoping to be out portable on 23cms Tomorrow

Dave - G4RQI
 

Hello Nick

 

I currently have 23cm up but I am only QRV after 5:30pm so what time are you going to be out and what is your locator going to be?

 

73 David – G4RQI

Sent from Mail for Windows 10

 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Nick Gregory G0HIK via Groups.Io <nickg0hik@...>
Sent: Sunday, September 15, 2019 4:07:25 PM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: [UKMicrowaves] I'm hoping to be out portable on 23cms Tomorrow
 
As per the header.

I'll be out with 23cms and 2mtrs tomorrow from one of the Lake district fells. Mainly to work Andrew G4VFL/P, but happy to work anyone.

I'll have Zello, but internet is flakey on Kirkby Moor, so a Text may be better 07955635646.

Nick G0HIK

Re: milling copper

geoffrey pike
 

Thanks all, i will give a 2 flute mill a try, this 4 flute is digging in, oh and more rpm
cheers
Geoff
GI0GDP

On Sunday, 15 September 2019, 07:47:07 BST, DougF <uwaves@...> wrote:


Greetings to all.

My experience is that I have met my copper drilling/tapping/milling
needs by way of purchase of drill bits, taps and milling cutters which
are intended for use in cutting copper.  They do exist!  They also are
great when trying to work with brass, some alloys of which are tough and
likely to break whichever tool is in use.

FWIW.....

--Doug Friend, VK4OE.

On 15/09/2019 3:51 pm, Mike Willis wrote:
> Best solution, find someone else to do it who can do it properly.
> Otherwise you get a poor finish, or a tap breaking and getting stuck
> just as you tap the last of 20 holes.
> Mike G0MJW


I'm hoping to be out portable on 23cms Tomorrow

Nick Gregory G0HIK
 

As per the header.

I'll be out with 23cms and 2mtrs tomorrow from one of the Lake district fells. Mainly to work Andrew G4VFL/P, but happy to work anyone.

I'll have Zello, but internet is flakey on Kirkby Moor, so a Text may be better 07955635646.

Nick G0HIK

Re: Looking for a 1N78BR detector diode

Rien Eradus PA0JME
 

Hi Arved, found 1N78BAR in my "junkbox" sealed in lead shroud, usefull?

My guess the R is for reversed, I did not test it with an ohm-meter since these diodes are known to be fragile.

I kept them for possible 24 GHz experiments, made my first qso there with Hans PA0DBQ, next month 40 years ago hi

Nowadays more modern stuff is at hand.

Best regards Rien

Op 14-9-2019 om 23:17 schreef Arved M0KDS:


Here are some pictures of the diode itself: 




Re: Millimetre Contest 15th September

Roger Ray
 

Slight change of plan.
First location IO91BL16 Clyffe Pypard
second IO91CL35 Hackpen
third if possible. IO91DL68

talk back 144.390, kst, mob: 07900 261121
Difficult to predict moving times, although only expect to be at the first location for an hour or so.

Roger
G8CUB

Re: milling copper

DougF VK4OE
 

Greetings to all.

My experience is that I have met my copper drilling/tapping/milling needs by way of purchase of drill bits, taps and milling cutters which are intended for use in cutting copper.  They do exist!  They also are great when trying to work with brass, some alloys of which are tough and likely to break whichever tool is in use.

FWIW.....

--Doug Friend, VK4OE.

On 15/09/2019 3:51 pm, Mike Willis wrote:
Best solution, find someone else to do it who can do it properly. Otherwise you get a poor finish, or a tap breaking and getting stuck just as you tap the last of 20 holes.
Mike G0MJW

Re: milling copper

Mike Willis
 

Best solution, find someone else to do it who can do it properly. Otherwise you get a poor finish, or a tap breaking and getting stuck just as you tap the last of 20 holes.
--
Mike G0MJW

Re: milling copper

Peter Torry
 

Hi Geoff,

Not sure which type is better but I have found that lubrication of the cutter with either kerosene or white spirit improves the cut and reduces the "stickiness" of the copper.

73

Peter    G3SMT


On 14/09/2019 22:12, geoffrey pike via Groups.Io wrote:
Is it any better to use a 2 flute mill instead of a 4 flute end mill to cut slots in copper plate
said slot is for LDMOS device to be soldered in,
cheers
Geoff
GI0GDP

--
Peter G3SMT

Re: milling copper

Neil Smith G4DBN
 

I use a 2-flute polished (uncoated) slot drill. With a 10mm cutter, I run 1200rpm and 75mm/minute, with WD40 lubricant.  I have used a three-flute carbide end mill as well, but the fast-helix cutters designed for high-rate machining of aluminium work best for me.

Top trick though is to avoid C101 and use C111 (or C109 if you can find it). C111 machines with nice short chips, doesn't tear, isn't gummy and doesn't build up on the tool edge like 101.

Neil G4DBN

On 14/09/2019 22:12, geoffrey pike via Groups.Io wrote:
Is it any better to use a 2 flute mill instead of a 4 flute end mill to cut slots in copper plate
said slot is for LDMOS device to be soldered in,
cheers
Geoff
GI0GDP

Re: Looking for a 1N78BR detector diode

Arved M0KDS
 


Here are some pictures of the diode itself: 




milling copper

geoffrey pike
 

Is it any better to use a 2 flute mill instead of a 4 flute end mill to cut slots in copper plate
said slot is for LDMOS device to be soldered in,
cheers
Geoff
GI0GDP

Looking for a 1N78BR detector diode

Arved M0KDS
 

Hi all,

it seems like the detector diode in the first mixer of my old systron donner analyzer has failed. It was suggested to me that the 1N78BR diode could act as a replacement. I found one on eBay from Germany, but I thought it may be worth asking in here too before making the purchase. I'm not entirely sure if other diodes could work as well as the diode has to physically fit into the mounting hole of the mixer. 

Many thanks and 73,

Arved M0KDS

Re: Farnham 3.4GHz Beacon Test

G4LDR
 

Hi Dave,

Further to my post of a few minutes ago, I've just checked the 6cm Farnham beacon and it is 599++ (virtually end stop) so there is a lift on at the moment. I'll monitor the 9cm beacon over the next few days and see what strength it is under flat band contitions.

73 Neil G4LDR.

Re: Farnham 3.4GHz Beacon Test

G4LDR
 

Hello Dave,

Just got round to listening for the new Farnham 3.4GHz Beacon.

It is currently 599 and a fairly steady signal (tower in lowered position and beaming straight into the trees that screen the lower part of the tower). I'm 61km from the beacon and it is a quite an obstructed path. Frequency measured here is 3400.740500MHz. I'm able to hear it no matter which way the dish is pointing. Hope it becomes a permanent feature. (For reference the 13cm beacon is 599++ and the 6cm beacon from the other Farnham site is usually only 519 ish).

Thanks for getting it on the air.

73 Neil G4LDR

Re: Millimetre Contest 15th September

David Robinson
 

I was at Io82lb this afternoon for the batc datv lowband contest, on 24g zme was loud on open waveguide so that band seems to work, not so convinced about my 47g system though
Will be qrv on 24 at 1200z when 4m afs finishes

Dave
G4fre/p

Re: Millimetre Contest 15th September

Roger Ray
 

I will be at Hackpen for longer, as the second location has too many trees. Likely I will move somewhere later.
Roger
G8CUB

Re: Millimetre Contest 15th September

Keith GW3TKH
 

Pete and I will be QRV form the usual place, IO81LS19. Both with 24, 47 and 76GHz.

Time from 0900 UTC, talk back via 144.390, KST, 07762885015.

73 Keith
GW3TKH



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Re: Millimetre Contest 15th September

G4LDR
 

I should be QRV on 24, 47 and 76GHz.

Probable locations are Salisbury Plain area and south west Hampshire.

Times from about 09:00UTC.

Talkback, mainly 144.390 (+/- QSY), and possibly KST.

73 Neil G4LDR

Spectrum analysers

Michael Scott
 

Hi All
 
All the SA units have been claimed, sorry!
 
Mike

Re: 122GHz Chip Transceiver

Andy G4JNT
 


On Sat, 14 Sep 2019 at 12:20, Andy G4JNT via Groups.Io <andy.g4jnt=gmail.com@groups.io> wrote:
Interesting article in the latest Dubus about a Siliconradar chip used as a transceiver for 122GHz

The chip itself has a VCO (with output at 1.9GHz from an internal  prescaler) , 0.5mW PA , LNA and quadrature downconversion to 0 - 200MHz IF

By adding of a Fract-N synth the chip can be locked and you have a standalone 122GHz transceiver for CW and any modulation  that can be done by changing the frequency .   A modern Fract-N with tiny frequency resolution will allow quite narrow step size.

Downside is, it has separate Tx and Rx antennas so mounting on a dish is problematical.   The chip can be physically shifted between Tx/Rx, or the authors have designed a combiner.

Interesting ....