[VHFcontesting] A handful of questions

Sean Waite waisean at gmail.com
Mon Jul 11 11:08:30 EDT 2016


On Mon, Jul 11, 2016 at 7:22 AM Jarred Jackson <Jarred.Jackson at hotmail.com>

> Sean,
> I can provide input on some of your questions. No experience with 100W
> attenuators, but I have an IC-7000 and it has band selectable power output.
> This means you can run 100W on 6m and 5W on 2m and never have to touch it
> after setup. For a little over a year I ran the IC-7000 from 50 - 1296 MHz
> with an Elecraft transverter on 222, DEMI 902/3, and the SG-Lab 1296
> transverter. I setup the 2m amplifier with the same power input as the
> transverters needed. If there was any power spiking, it was not detectable
> with a simple power/swr meter. As I added additional microwave bands, I
> have moved all transverters to an 817.

We weren't aware of the selectable power on the IC-7000. That's very
convenient, particularly since we can use the 10m band as IF on 222. The
IC-746 can't do that as far as I can tell, it's got a knob.

I'm not particularly concerned about the SG-Lab 1296 power output for
roving, 2 or 5 watts isn't huge and I'll have a beam making up most of
that. More of a concern is if I'd be losing too much if I put it into a
100W amp and not having as much input power to drive it.

> In terms of power on 1296, I ran the SG-Labs transverter barefoot for over
> a year and did well with it. Not sure how this happened, but I was the
> rover grid leader for 1296 this past January using this setup. 8 grids on
> 1296 when visiting 4.   In June I added a 10W amplifier and worked 7 grids
> having visited 6. I assure you that assistance, advanced coordination and
> timing were more important to me than power. If you compare rover 1296 QSO
> leaders to Grid leaders (see ARRL full results) in the January contest you
> will quickly recognize that a majority of the contacts  from the top
> rovers are coming from inside of the grids visited (a majority with club
> members and cooperative rovers). The SG-Labs transverter and a 6 foot
> antenna will do great under these circumstances. Good $/QSO value overall.

I was looking at the SG-Labs transverter and a 6' Directive Systems loop
yagi, so this is good to hear.

> In terms of locations, publishing detailed schedules in advance and asking
> for detailed schedules from others seems to be the best way of avoiding too
> much trouble. You can sometimes predict the schedule of the experienced
> rovers in the area looking in the VHF contesting archives and getting in
> touch with those likely to use the site weeks before the contest. However a
> rover schedule is just a swag and you need to be prepared for someone to be
> on location when they are not expected to be (it will happen to you too).
> Interference is nearly certain. If the other rover has 2-ops calling CQ
> regularly on 2 bands, this will cause frustration. You can coordinate with
> a more casual single op much easier. Its also interesting to chat and take
> a look at another rover setup in person.

This is what I was concerned about, we're going to have 2 ops calling on 2
and 6 a whole lot, so we'd be clobbering others and they'd be clobbering
us. I intend on asking the local VHF group (NEWS) for tips on locations so
hopefully we'll be able to avoid interference.

> I have done well with 4-6 grids. I cannot operate much in motion (FM only)
> and it takes 10-20 minutes each for setup and teardown at east site. I
> suggest adding 45-60 minutes of extra time for the first couple of sites
> for "uncertainty" and troubleshooting when making your plans. Dont forget
> to add time to get gas, grab a bite to eat and use the facilities. I have
> yet to stick to a schedule very well, so this is still a work in progress
> for me.

4-6 seems reasonable, and is about what I was aiming for. There aren't
great grid junctions out here, so I probably won't be able to do a
multi-grid location, but we've got some mountains with parking lots on them.

> Good Luck
> Jarred - KF2MR


> ------------------------------
> *From:* VHFcontesting <vhfcontesting-bounces at contesting.com> on behalf of
> Sean Waite <waisean at gmail.com>
> *Sent:* Sunday, July 10, 2016 11:58 PM
> *To:* VHF Contesting
> *Subject:* [VHFcontesting] A handful of questions
> Hey everyone,
> I'm working on getting my rover together (first time out, should be a hoot)
> for September and am running into some questions.
> We're looking at picking up transverters for 222 and 1296. Does anyone have
> a good source of 100W attenuators for the IFs on these? 222 would have a
> 10m IF, 1296 would be 2m. It looks like most of them expect a 5W input, and
> I can spin the power knob to cut the radio down that low, but if I forget
> then I'd let the magic smoke out. Failing a reasonably priced attenuator
> (with a T/R relay I'd assume), one thing I've heard is that 100W rigs can
> sometimes spike in power if you have them turned all of the way down. My
> IC-746 will do 5W minimum, is this safe to pump into a transverter? We'll
> also have an IC-7000.
> For 1296, I was looking at the sg-labs 23cm transverter. It looks like a
> reasonable price, and people seem happy with them. The concern I have is
> the 2W out, vs 5W of many transverters. I'd like to eventually put an amp
> behind this to get more power out, would the 2W be a problem for most
> things from DEMI/Kuhne/etc? The price of this may mean the difference from
> being QRV on 23cm this contest or not, the Kuhne 23cm gear might eliminate
> me getting an antenna as well, except for maybe one of those silly pcb
> yagis from WA5VJB. My goal is to eventually get up on 23cm EME, even if
> it's only a small station (which it will be).
> My friend was also wondering if there was an inexpensive 10m only rig. The
> HTX-10 is in the right price range, but without surgery it cannot reduce
> power to something that a transverter can use. Any suggestions?
> My rover plans are coming along. I have power figured out, parts are on
> their way, and we're working on accumulating antennas and other bits. We're
> looking around at some of the links I received previously, and other maps,
> to try and pick our operation locations. We may start at FN51 and loop
> around through several grids to end up in our home FN42 at the end. Having
> never done this before, we have no idea how many grids is reasonable, but
> we'll figure it out. One plan is to come up with the start and end points
> for each day, and then a few grids in between to hit as we can. I'm
> thinking maybe 3 grids on Saturday and 2 on Sunday.
> One thing I'm not sure about is what happens if a site is occupied by
> another rover, and if it's okay to park in the vicinity or if I should move
> away further to avoid QRM. At least it would be an easy contact.
> Thanks and 73, hope to see you on the air in September.
> Sean WA1TE
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