Search found 501 matches

by VK3QI
Tue Jul 16, 2019 12:28 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Adam, I think there might be more "smarts" than that shown in that circuit diagram. I don't have access to the HM-219 but other mikes in the series also have similar PTT switching - which in reality is just a switched line to earth. Maybe the smarts are associated with the input circuit board in the...
by VK3QI
Mon Jul 15, 2019 9:35 pm
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Adam,

Here is a link to the circuit diagram.

http://www.g4izh.co.uk/microphone-input ... ement.html

Scroll down about half way.

I presume that the diode must act as some sort of spike shunt, coupled with the low Q of the shunted 10n capacitor.

Cheers

Peter VK3QI
by VK3QI
Fri Jul 05, 2019 4:26 pm
Forum: Satellites & Balloons
Topic: Satellite ops with IC-9700
Replies: 7
Views: 222

Re: Satellite ops with IC-9700

Adam, Just another example of where the TS2000 with its individual band PTT outputs has it all over the Icom rigs. The matter is now worse than ever. In previous Icom models, you had the ability to use the VSEND setting to UHF, which meant you could set the VSEND to 70cm. and 23cm. and the HSEND to ...
by VK3QI
Sat Jun 22, 2019 10:14 am
Forum: 1296, Microwaves and Opto
Topic: GPSDO Phase noise
Replies: 13
Views: 615

Re: GPSDO Phase noise and BG7TBL distribution amplifer

Dave, Although not exactly related to what we were discussing before, I came across an interesting effect yesterday whilst setting up a rover station. I was using one of the GPS units previously discussed feeding into a BG7TBL 8 port distribution amplifier with an in-built OXCO as a backup. I alread...
by VK3QI
Fri Jun 21, 2019 6:06 pm
Forum: General Discussion
Topic: Interview with Jet Jurgensmeyer KE0UWZ about Last Man Standing & Ham Radio
Replies: 2
Views: 136

Re: Interview with Jet Jurgensmeyer KE0UWZ about Last Man Standing & Ham Radio

Great interview Hayden. Unlike many interviewers who spend too much time talking themselves, you gave Jet great opportunities to show his manners and confidence to the viewers. I would like to think that an organisation like the ARRL would pick up this video and promote it - I am sure that Jet has a...
by VK3QI
Fri Jun 07, 2019 10:25 pm
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

This coupler method was popularised by the late G4HUP and he actually sold a kit to that effect. The only comment I would make is that it does require a retune of the coil to which you have coupled the signal. Given that the IC9700 produces and requires subharmonics as well, there is no guarantee th...
by VK3QI
Thu Jun 06, 2019 10:20 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Adam, The last line in Sam, G4DDK's post says it all: "so far so good, but the oscillator definitely needs locking for serious use!" Based on some other naïve posts made recently about features in the IC9700, I suspect that the earlier post regrading the European Icom engineers, is old news and stil...
by VK3QI
Wed May 29, 2019 8:37 pm
Forum: 1296, Microwaves and Opto
Topic: GPSDO Phase noise
Replies: 13
Views: 615

Re: GPSDO Phase noise

Dave, I have been using a number of those cheaper units successfully for quite a while now up to and including 47 GHz. I obtain them from Ebay seller RFEXPERTS https://www.ebay.com.au/itm/NEW-10MHz-Sinwave-PLL-GPSDO-GPS-DISCIPLINED-OSCILLATOR-adapter-GPS-ANT/262038924752?ssPageName=STRK%3AMEBIDX%3AI...
by VK3QI
Sun May 12, 2019 10:11 am
Forum: General Discussion
Topic: 50 years
Replies: 5
Views: 205

Re: 50 years

Great effort Steve. Always good to see someone who has stuck at it for so long with a consistent work ethic and work history. I have just finished 50 years with DET Victoria and feel the same way about having a consistent ethic throughout one's career. Good health to you in the future! (and of cours...
by VK3QI
Fri May 10, 2019 9:32 am
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Rod, I understand what you are saying and it makes sense if all WiFi equipment was meeting the standard, but as we all know, the denser the population, the more likely you are to find non compliant devices. Essentially operating from home in Melbourne, 8 kms east of the city, the whole band has "squ...
by VK3QI
Thu May 09, 2019 11:48 pm
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Rod,

Doesn't your first picture (4302 MHz centre, 4 MHz span) show that 2403 is clear, just like 2400?

The results we have had are relatively similar to yours - that is, the WIFI noise tends to peak on the even frequencies, although the reason for that is not clear.

Peter VK3QI
by VK3QI
Thu May 09, 2019 12:36 pm
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Hayden, A bit of background. Likely terrestrial contacts with New Zealand, New Caledonia and Indonesia. NEW ZEALAND http://www.nzart.org.nz/assets/bandplan/2018-bandplan.pdf JAPAN (EME) https://jarl.org/English/6_Band_Plan/JapaneseAmateurBandplans20150105.pdf FRANCE = PRESUMABLY NEW CALEDONIA AS WEL...
by VK3QI
Thu May 09, 2019 12:14 pm
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Hayden, I am not fully aware of the earlier history of using 13cm. (pre-2002), but I do note that 2300 to 2302 is only available to Advanced licences, whereas Standard licences can use 2400- 2450. The use of 2300 - 2302 was not always available to VK amateurs. Maybe one of the EME enthusiasts can en...
by VK3QI
Thu May 09, 2019 1:32 am
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Fair enough Iain, Interestingly, in Melbourne the 2403 region is often "quieter" than the 2400 region. It all seems to depend on where the dish is pointed and how many wifi devices are switched on in the immediate area at any particular time. Often I can see upwards of 10 users just on my laptop sit...
by VK3QI
Wed May 08, 2019 6:24 pm
Forum: 1296, Microwaves and Opto
Topic: 13 cm calling frequency.
Replies: 15
Views: 555

Re: 13 cm calling frequency.

Trevor, There is a problem with your proposal. 2400 - 2403 is set aside as Amateur Satellites according to the recommended band plan, with a note that the satellite section should be kept clear of all terrestrial operations. That is why 2403.150 has become the de-facto calling frequency in VK3/7 and...
by VK3QI
Fri May 03, 2019 10:07 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Good morning, Having had a chance now to study the IC9700 service manual, it MAY give a clue as to why the IC 9700 is not 10 Mhz locked. The master oscillator is 49.152MHz. In order to produce RECEPTION on the 1240 - 1300 MHz band, the IF frequencies of 311 Mhz to 371 MHz are produced by mixing a co...
by VK3QI
Thu May 02, 2019 8:33 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Steve, The simple answer amongst all the various suggestions being put forward, is that Icom should have made possible a 10Mhz locking option, as they have done with the 7610 model. There may be technical difficulties in doing so, given the constraints on using SDR up to 440 MHz, but we need to wait...
by VK3QI
Fri Apr 26, 2019 10:52 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Good question Adam. Hopefully the Icom engineers will bring out a series of technical reports (http://www.icom.co.jp/world/products/amateur/hf/ic-7610/IC-7610_Technical_Report_Vol2_Eng.pdf) like they did with the IC7610 explaining why they didn't implement 10MHz locking and explaining why they neede...
by VK3QI
Fri Apr 26, 2019 10:06 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Hayden, I haven't spoken with David and Graham 3XDK for quite some time. But the problem of producing a GPS locked 49.152MHz signal is not really the issue. VHF Design, Leo Bodnar and others can all produce such a board --> the problem is getting it into the rig successfully, without compromising th...
by VK3QI
Fri Apr 26, 2019 9:48 am
Forum: Transceivers, Transmitters & Receivers
Topic: Icom IC-9700 users topic
Replies: 146
Views: 6930

Re: Icom IC-9700 users topic

Hayden, I sent a message to Rex after the post from VK1XX about the 49.152 TCXO, but I am not sure if he saw it. My comments related to the implementation of the SDR up to 450MHz, which, for good RMDR requires clear processing power up to 900 MHz. Icom are the first of the "ham" manufacturers to imp...